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* [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes
@ 2020-06-17  8:30 Alexey Budankov
  2020-06-17  8:35 ` [PATCH v8 01/13] tools/libperf: avoid moving of fds at fdarray__filter() call Alexey Budankov
                   ` (13 more replies)
  0 siblings, 14 replies; 49+ messages in thread
From: Alexey Budankov @ 2020-06-17  8:30 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Jiri Olsa, Namhyung Kim, Alexander Shishkin, Peter Zijlstra,
	Ingo Molnar, Andi Kleen, linux-kernel


Changes in v8:
- avoided moving of fds at fdarray__filter() call
- skipped counting of fds with zeroed revents at fdarray__filter() call
- converted explicit --ctl-fd[-ack] into --control fd:ctl-fd[,ack-fd option 
- updated docs to accommodate --control fd:ctl-fd[,ack-fd] option

v7: https://lore.kernel.org/lkml/5de4b954-24f0-1e8d-5a0d-7b12783b8218@linux.intel.com/

Changes in v7:
- added missing perf-record.txt changes 
- adjusted docs wording for --ctl-fd,ctl-fd-ack options 
  to additionally mention --delay=-1 effect

v6: https://lore.kernel.org/lkml/f8e3a714-d9b1-4647-e1d2-9981cbaa83ec@linux.intel.com/

Changes in v6:
- split re-factoring of events handling loops for stat mode
  into smaller incremental parts
- added parts missing at v5
- corrected v5 runtime issues

v5: https://lore.kernel.org/lkml/e5cac8dd-7aa4-ec7c-671c-07756907acba@linux.intel.com/

Changes in v5:
- split re-factoring of events handling loops for stat mode
  into smaller incremental parts

v4: https://lore.kernel.org/lkml/653fe5f3-c986-a841-1ed8-0a7d2fa24c00@linux.intel.com/

Changes in v4:
- made checking of ctlfd state unconditional in record trace streaming loop
- introduced static poll fds to keep evlist__filter_pollfd() unaffected
- handled ret code of evlist__initialize_ctlfd() where need
- renamed and structured handle_events() function
- applied anonymous structs where needed

v3: https://lore.kernel.org/lkml/eb38e9e5-754f-d410-1d9b-e26b702d51b7@linux.intel.com/

Changes in v3:
- renamed functions and types from perf_evlist_ to evlist_ to avoid
  clash with libperf code;
- extended commands to be strings of variable length consisting of
  command name and also possibly including command specific data;
- merged docs update with the code changes;
- updated docs for -D,--delay=-1 option for stat and record modes;

v2: https://lore.kernel.org/lkml/d582cc3d-2302-c7e2-70d3-bc7ab6f628c3@linux.intel.com/

Changes in v2:
- renamed resume and pause commands to enable and disable ones, renamed
  CTL_CMD_RESUME and CTL_CMD_PAUSE to CTL_CMD_ENABLE and CTL_CMD_DISABLE
  to fit to the appropriate ioctls and avoid mixing up with PAUSE_OUTPUT
  ioctl;
- factored out event handling loop into a handle_events() for stat mode;
- separated -D,--delay=-1 into separate patches for stat and record modes;

v1: https://lore.kernel.org/lkml/825a5132-b58d-c0b6-b050-5a6040386ec7@linux.intel.com/

repo: tip of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git perf/core

The patch set implements handling of 'start disabled', 'enable' and 'disable'
external control commands which can be provided for stat and record modes
of the tool from an external controlling process. 'start disabled' command
can be used to postpone enabling of events in the beginning of a monitoring
session. 'enable' and 'disable' commands can be used to enable and disable
events correspondingly any time after the start of the session.

The 'start disabled', 'enable' and 'disable' external control commands can be
used to focus measurement on specially selected time intervals of workload
execution. Focused measurement reduces tool intrusion and influence on
workload behavior, reduces distortion and amount of collected and stored
data, mitigates data accuracy loss because measurement and data capturing
happen only during intervals of interest.

A controlling process can be a bash shell script [1], native executable or
any other language program that can directly work with file descriptors,
e.g. pipes [2], and spawn a process, specially the tool one.

-D,--delay <val> option is extended with -1 value to skip events enabling
in the beginning of a monitoring session ('start disabled' command).
--control fd:ctl-fd[,ack-fd] command line option is introduced to provide the
tool with a pair of file descriptors to listen to control commands and reply
to the controlling process on the completion of received commands.

The tool reads control command message from ctl-fd descriptor, handles the
command and optionally replies acknowledgement message to ack-fd descriptor,
if it is specified on the command line. 'enable' command is recognized as
'enable' string message and 'disable' command is recognized as 'disable'
string message both received from ctl-fd descriptor. Completion message is
'ack\n' and sent to ack-fd descriptor.

Example bash script demonstrating simple use case follows:

#!/bin/bash

ctl_dir=/tmp/

ctl_fifo=${ctl_dir}perf_ctl.fifo
test -p ${ctl_fifo} && unlink ${ctl_fifo}
mkfifo ${ctl_fifo} && exec {ctl_fd}<>${ctl_fifo}

ctl_ack_fifo=${ctl_dir}perf_ctl_ack.fifo
test -p ${ctl_ack_fifo} && unlink ${ctl_ack_fifo}
mkfifo ${ctl_ack_fifo} && exec {ctl_fd_ack}<>${ctl_ack_fifo}

perf stat -D -1 -e cpu-cycles -a -I 1000       \
          --control fd:${ctl_fd},${ctl_fd_ack} \
          -- sleep 40 &
perf_pid=$!

sleep 5  && echo 'enable' >&${ctl_fd} && read -u ${ctl_fd_ack} e1 && echo "enabled(${e1})"
sleep 10 && echo 'disable' >&${ctl_fd} && read -u ${ctl_fd_ack} d1 && echo "disabled(${d1})"
sleep 5  && echo 'enable' >&${ctl_fd} && read -u ${ctl_fd_ack} e2 && echo "enabled(${e2})"
sleep 10 && echo 'disable' >&${ctl_fd} && read -u ${ctl_fd_ack} d2 && echo "disabled(${d2})"

exec {ctl_fd_ack}>&- && unlink ${ctl_ack_fifo}
exec {ctl_fd}>&- && unlink ${ctl_fifo}

wait -n ${perf_pid}
exit $?


Script output:

[root@host dir] example
Events disabled
#           time             counts unit events
     1.001101062      <not counted>      cpu-cycles                                                  
     2.002994944      <not counted>      cpu-cycles                                                  
     3.004864340      <not counted>      cpu-cycles                                                  
     4.006727177      <not counted>      cpu-cycles                                                  
Events enabled
enabled(ack)
     4.993808464          3,124,246      cpu-cycles                                                  
     5.008597004          3,325,624      cpu-cycles                                                  
     6.010387483         83,472,992      cpu-cycles                                                  
     7.012266598         55,877,621      cpu-cycles                                                  
     8.014175695         97,892,729      cpu-cycles                                                  
     9.016056093         68,461,242      cpu-cycles                                                  
    10.017937507         55,449,643      cpu-cycles                                                  
    11.019830154         68,938,167      cpu-cycles                                                  
    12.021719952         55,164,101      cpu-cycles                                                  
    13.023627550         70,535,720      cpu-cycles                                                  
    14.025580995         53,240,125      cpu-cycles                                                  
disabled(ack)
    14.997518260         53,558,068      cpu-cycles                                                  
Events disabled
    15.027216416      <not counted>      cpu-cycles                                                  
    16.029052729      <not counted>      cpu-cycles                                                  
    17.030904762      <not counted>      cpu-cycles                                                  
    18.032073424      <not counted>      cpu-cycles                                                  
    19.033805074      <not counted>      cpu-cycles                                                  
Events enabled
enabled(ack)
    20.001279097          3,021,022      cpu-cycles                                                  
    20.035044381          6,434,367      cpu-cycles                                                  
    21.036923813         89,358,251      cpu-cycles                                                  
    22.038825169         72,516,351      cpu-cycles                                                  
#           time             counts unit events
    23.040715596         55,046,157      cpu-cycles                                                  
    24.042643757         78,128,649      cpu-cycles                                                  
    25.044558535         61,052,428      cpu-cycles                                                  
    26.046452785         62,142,806      cpu-cycles                                                  
    27.048353021         74,477,971      cpu-cycles                                                  
    28.050241286         61,001,623      cpu-cycles                                                  
    29.052149961         61,653,502      cpu-cycles                                                  
disabled(ack)
    30.004980264         82,729,640      cpu-cycles                                                  
Events disabled
    30.053516176      <not counted>      cpu-cycles                                                  
    31.055348366      <not counted>      cpu-cycles                                                  
    32.057202097      <not counted>      cpu-cycles                                                  
    33.059040702      <not counted>      cpu-cycles                                                  
    34.060843288      <not counted>      cpu-cycles                                                  
    35.000888624      <not counted>      cpu-cycles                                                  
[root@host dir]# 

[1] http://man7.org/linux/man-pages/man1/bash.1.html
[2] http://man7.org/linux/man-pages/man2/pipe.2.html

---
Alexey Budankov (13):
  tools/libperf: avoid moving of fds at fdarray__filter() call
  perf evlist: introduce control file descriptors
  perf evlist: implement control command handling functions
  perf stat: factor out body of event handling loop for system wide
  perf stat: move target check to loop control statement
  perf stat: factor out body of event handling loop for fork case
  perf stat: factor out event handling loop into dispatch_events()
  perf stat: extend -D,--delay option with -1 value
  perf stat: implement control commands handling
  perf stat: introduce --control fd:ctl-fd[,ack-fd] options
  perf record: extend -D,--delay option with -1 value
  perf record: implement control commands handling
  perf record: introduce --control fd:ctl-fd[,ack-fd] options

 tools/lib/api/fd/array.c                 |  11 +-
 tools/perf/Documentation/perf-record.txt |  44 +++++-
 tools/perf/Documentation/perf-stat.txt   |  44 +++++-
 tools/perf/builtin-record.c              |  65 ++++++++-
 tools/perf/builtin-stat.c                | 176 ++++++++++++++++++-----
 tools/perf/builtin-trace.c               |   2 +-
 tools/perf/tests/fdarray.c               |  20 +--
 tools/perf/util/evlist.c                 | 136 ++++++++++++++++++
 tools/perf/util/evlist.h                 |  25 ++++
 tools/perf/util/record.h                 |   4 +-
 tools/perf/util/stat.h                   |   4 +-
 11 files changed, 458 insertions(+), 73 deletions(-)

-- 
2.24.1

^ permalink raw reply	[flat|nested] 49+ messages in thread

* [PATCH v8 01/13] tools/libperf: avoid moving of fds at fdarray__filter() call
  2020-06-17  8:30 [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
@ 2020-06-17  8:35 ` Alexey Budankov
  2020-06-24 17:19   ` Alexey Budankov
  2020-06-17  8:35 ` [PATCH v8 02/13] perf evlist: introduce control file descriptors Alexey Budankov
                   ` (12 subsequent siblings)
  13 siblings, 1 reply; 49+ messages in thread
From: Alexey Budankov @ 2020-06-17  8:35 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Jiri Olsa, Namhyung Kim, Alexander Shishkin, Peter Zijlstra,
	Ingo Molnar, Andi Kleen, linux-kernel


Skip fds with zeroed revents field from count and avoid fds moving
at fdarray__filter() call so fds indices returned by fdarray__add()
call stay the same and can be used for direct access and processing
of fd revents status field at entries array of struct fdarray object.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 tools/lib/api/fd/array.c   | 11 +++++------
 tools/perf/tests/fdarray.c | 20 ++------------------
 2 files changed, 7 insertions(+), 24 deletions(-)

diff --git a/tools/lib/api/fd/array.c b/tools/lib/api/fd/array.c
index 58d44d5eee31..97843a837370 100644
--- a/tools/lib/api/fd/array.c
+++ b/tools/lib/api/fd/array.c
@@ -93,22 +93,21 @@ int fdarray__filter(struct fdarray *fda, short revents,
 		return 0;
 
 	for (fd = 0; fd < fda->nr; ++fd) {
+		if (!fda->entries[fd].revents)
+			continue;
+
 		if (fda->entries[fd].revents & revents) {
 			if (entry_destructor)
 				entry_destructor(fda, fd, arg);
 
+			fda->entries[fd].revents = fda->entries[fd].events = 0;
 			continue;
 		}
 
-		if (fd != nr) {
-			fda->entries[nr] = fda->entries[fd];
-			fda->priv[nr]	 = fda->priv[fd];
-		}
-
 		++nr;
 	}
 
-	return fda->nr = nr;
+	return nr;
 }
 
 int fdarray__poll(struct fdarray *fda, int timeout)
diff --git a/tools/perf/tests/fdarray.c b/tools/perf/tests/fdarray.c
index c7c81c4a5b2b..d0c8a05aab2f 100644
--- a/tools/perf/tests/fdarray.c
+++ b/tools/perf/tests/fdarray.c
@@ -12,6 +12,7 @@ static void fdarray__init_revents(struct fdarray *fda, short revents)
 
 	for (fd = 0; fd < fda->nr; ++fd) {
 		fda->entries[fd].fd	 = fda->nr - fd;
+		fda->entries[fd].events  = revents;
 		fda->entries[fd].revents = revents;
 	}
 }
@@ -29,7 +30,7 @@ static int fdarray__fprintf_prefix(struct fdarray *fda, const char *prefix, FILE
 
 int test__fdarray__filter(struct test *test __maybe_unused, int subtest __maybe_unused)
 {
-	int nr_fds, expected_fd[2], fd, err = TEST_FAIL;
+	int nr_fds, err = TEST_FAIL;
 	struct fdarray *fda = fdarray__new(5, 5);
 
 	if (fda == NULL) {
@@ -55,7 +56,6 @@ int test__fdarray__filter(struct test *test __maybe_unused, int subtest __maybe_
 
 	fdarray__init_revents(fda, POLLHUP);
 	fda->entries[2].revents = POLLIN;
-	expected_fd[0] = fda->entries[2].fd;
 
 	pr_debug("\nfiltering all but fda->entries[2]:");
 	fdarray__fprintf_prefix(fda, "before", stderr);
@@ -66,17 +66,9 @@ int test__fdarray__filter(struct test *test __maybe_unused, int subtest __maybe_
 		goto out_delete;
 	}
 
-	if (fda->entries[0].fd != expected_fd[0]) {
-		pr_debug("\nfda->entries[0].fd=%d != %d\n",
-			 fda->entries[0].fd, expected_fd[0]);
-		goto out_delete;
-	}
-
 	fdarray__init_revents(fda, POLLHUP);
 	fda->entries[0].revents = POLLIN;
-	expected_fd[0] = fda->entries[0].fd;
 	fda->entries[3].revents = POLLIN;
-	expected_fd[1] = fda->entries[3].fd;
 
 	pr_debug("\nfiltering all but (fda->entries[0], fda->entries[3]):");
 	fdarray__fprintf_prefix(fda, "before", stderr);
@@ -88,14 +80,6 @@ int test__fdarray__filter(struct test *test __maybe_unused, int subtest __maybe_
 		goto out_delete;
 	}
 
-	for (fd = 0; fd < 2; ++fd) {
-		if (fda->entries[fd].fd != expected_fd[fd]) {
-			pr_debug("\nfda->entries[%d].fd=%d != %d\n", fd,
-				 fda->entries[fd].fd, expected_fd[fd]);
-			goto out_delete;
-		}
-	}
-
 	pr_debug("\n");
 
 	err = 0;
-- 
2.24.1


^ permalink raw reply related	[flat|nested] 49+ messages in thread

* [PATCH v8 02/13] perf evlist: introduce control file descriptors
  2020-06-17  8:30 [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
  2020-06-17  8:35 ` [PATCH v8 01/13] tools/libperf: avoid moving of fds at fdarray__filter() call Alexey Budankov
@ 2020-06-17  8:35 ` Alexey Budankov
  2020-06-17  8:36 ` [PATCH v8 03/13] perf evlist: implement control command handling functions Alexey Budankov
                   ` (11 subsequent siblings)
  13 siblings, 0 replies; 49+ messages in thread
From: Alexey Budankov @ 2020-06-17  8:35 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Jiri Olsa, Namhyung Kim, Alexander Shishkin, Peter Zijlstra,
	Ingo Molnar, Andi Kleen, linux-kernel


Define and initialize control file descriptors.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 tools/perf/util/evlist.c | 3 +++
 tools/perf/util/evlist.h | 5 +++++
 2 files changed, 8 insertions(+)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 173b4f0e0e6e..47541b5cab46 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -63,6 +63,9 @@ void evlist__init(struct evlist *evlist, struct perf_cpu_map *cpus,
 	perf_evlist__set_maps(&evlist->core, cpus, threads);
 	evlist->workload.pid = -1;
 	evlist->bkw_mmap_state = BKW_MMAP_NOTREADY;
+	evlist->ctl_fd.fd = -1;
+	evlist->ctl_fd.ack = -1;
+	evlist->ctl_fd.pos = -1;
 }
 
 struct evlist *evlist__new(void)
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index b6f325dfb4d2..0d8b361f1c8e 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -74,6 +74,11 @@ struct evlist {
 		pthread_t		th;
 		volatile int		done;
 	} thread;
+	struct {
+		int	fd;
+		int	ack;
+		int	pos;
+	} ctl_fd;
 };
 
 struct evsel_str_handler {
-- 
2.24.1



^ permalink raw reply related	[flat|nested] 49+ messages in thread

* [PATCH v8 03/13] perf evlist: implement control command handling functions
  2020-06-17  8:30 [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
  2020-06-17  8:35 ` [PATCH v8 01/13] tools/libperf: avoid moving of fds at fdarray__filter() call Alexey Budankov
  2020-06-17  8:35 ` [PATCH v8 02/13] perf evlist: introduce control file descriptors Alexey Budankov
@ 2020-06-17  8:36 ` Alexey Budankov
  2020-06-23 14:56   ` Jiri Olsa
  2020-06-23 14:56   ` Jiri Olsa
  2020-06-17  8:37 ` [PATCH v8 04/13] perf stat: factor out body of event handling loop for system wide Alexey Budankov
                   ` (10 subsequent siblings)
  13 siblings, 2 replies; 49+ messages in thread
From: Alexey Budankov @ 2020-06-17  8:36 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Jiri Olsa, Namhyung Kim, Alexander Shishkin, Peter Zijlstra,
	Ingo Molnar, Andi Kleen, linux-kernel


Implement functions of initialization, finalization and processing
of control command messages coming from control file descriptors.
Allocate control file descriptor as descriptor at struct pollfd
object of evsel_list for atomic poll() operation.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 tools/perf/util/evlist.c | 133 +++++++++++++++++++++++++++++++++++++++
 tools/perf/util/evlist.h |  17 +++++
 2 files changed, 150 insertions(+)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 47541b5cab46..11280ff559cd 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1718,3 +1718,136 @@ struct evsel *perf_evlist__reset_weak_group(struct evlist *evsel_list,
 	}
 	return leader;
 }
+
+int evlist__initialize_ctlfd(struct evlist *evlist, int fd, int ack)
+{
+	if (fd == -1) {
+		pr_debug("Control descriptor is not initialized\n");
+		return 0;
+	}
+
+	evlist->ctl_fd.pos = perf_evlist__add_pollfd(&evlist->core, fd, NULL, POLLIN);
+	if (evlist->ctl_fd.pos < 0) {
+		evlist->ctl_fd.pos = -1;
+		pr_err("Failed to add ctl fd entry: %m\n");
+		return -1;
+	}
+
+	evlist->ctl_fd.fd = fd;
+	evlist->ctl_fd.ack = ack;
+
+	return 0;
+}
+
+int evlist__finalize_ctlfd(struct evlist *evlist)
+{
+	struct pollfd *entries = evlist->core.pollfd.entries;
+
+	if (evlist->ctl_fd.pos == -1)
+		return 0;
+
+	entries[evlist->ctl_fd.pos].fd = -1;
+	entries[evlist->ctl_fd.pos].events = 0;
+	entries[evlist->ctl_fd.pos].revents = 0;
+
+	evlist->ctl_fd.pos = -1;
+	evlist->ctl_fd.ack = -1;
+	evlist->ctl_fd.fd = -1;
+
+	return 0;
+}
+
+static int evlist__ctlfd_recv(struct evlist *evlist, enum evlist_ctl_cmd *cmd,
+			      char *cmd_data, size_t data_size)
+{
+	int err;
+	char c;
+	size_t bytes_read = 0;
+
+	memset(cmd_data, 0, data_size--);
+
+	do {
+		err = read(evlist->ctl_fd.fd, &c, 1);
+		if (err > 0) {
+			if (c == '\n' || c == '\0')
+				break;
+			cmd_data[bytes_read++] = c;
+			if (bytes_read == data_size)
+				break;
+		} else {
+			if (err == -1)
+				pr_err("Failed to read from ctlfd %d: %m\n", evlist->ctl_fd.fd);
+			break;
+		}
+	} while (1);
+
+	pr_debug("Message from ctl_fd: \"%s%s\"\n", cmd_data,
+		 bytes_read == data_size ? "" : c == '\n' ? "\\n" : "\\0");
+
+	if (err > 0) {
+		if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG,
+			     strlen(EVLIST_CTL_CMD_ENABLE_TAG))) {
+			*cmd = EVLIST_CTL_CMD_ENABLE;
+		} else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG,
+				    strlen(EVLIST_CTL_CMD_DISABLE_TAG))) {
+			*cmd = EVLIST_CTL_CMD_DISABLE;
+		}
+	}
+
+	return err;
+}
+
+static int evlist__ctlfd_ack(struct evlist *evlist)
+{
+	int err;
+
+	if (evlist->ctl_fd.ack == -1)
+		return 0;
+
+	err = write(evlist->ctl_fd.ack, EVLIST_CTL_CMD_ACK_TAG,
+		    sizeof(EVLIST_CTL_CMD_ACK_TAG));
+	if (err == -1)
+		pr_err("failed to write to ctl_ack_fd %d: %m\n", evlist->ctl_fd.ack);
+
+	return err;
+}
+
+int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd)
+{
+	int err = 0;
+	char cmd_data[EVLIST_CTL_CMD_MAX_LEN];
+	int ctlfd_pos = evlist->ctl_fd.pos;
+	struct pollfd *entries = evlist->core.pollfd.entries;
+
+	if (ctlfd_pos == -1 || !entries[ctlfd_pos].revents)
+		return 0;
+
+	if (entries[ctlfd_pos].revents & POLLIN) {
+		err = evlist__ctlfd_recv(evlist, cmd, cmd_data,
+					 EVLIST_CTL_CMD_MAX_LEN);
+		if (err > 0) {
+			switch (*cmd) {
+			case EVLIST_CTL_CMD_ENABLE:
+				evlist__enable(evlist);
+				break;
+			case EVLIST_CTL_CMD_DISABLE:
+				evlist__disable(evlist);
+				break;
+			case EVLIST_CTL_CMD_ACK:
+			case EVLIST_CTL_CMD_UNSUPPORTED:
+			default:
+				pr_debug("ctlfd: unsupported %d\n", *cmd);
+				break;
+			}
+			if (!(*cmd == EVLIST_CTL_CMD_ACK || *cmd == EVLIST_CTL_CMD_UNSUPPORTED))
+				evlist__ctlfd_ack(evlist);
+		}
+	}
+
+	if (entries[ctlfd_pos].revents & (POLLHUP | POLLERR))
+		evlist__finalize_ctlfd(evlist);
+	else
+		entries[ctlfd_pos].revents = 0;
+
+	return err;
+}
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 0d8b361f1c8e..bccf0a970371 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -360,4 +360,21 @@ void perf_evlist__force_leader(struct evlist *evlist);
 struct evsel *perf_evlist__reset_weak_group(struct evlist *evlist,
 						 struct evsel *evsel,
 						bool close);
+#define EVLIST_CTL_CMD_ENABLE_TAG  "enable"
+#define EVLIST_CTL_CMD_DISABLE_TAG "disable"
+#define EVLIST_CTL_CMD_ACK_TAG     "ack\n"
+
+#define EVLIST_CTL_CMD_MAX_LEN 64
+
+enum evlist_ctl_cmd {
+	EVLIST_CTL_CMD_UNSUPPORTED = 0,
+	EVLIST_CTL_CMD_ENABLE,
+	EVLIST_CTL_CMD_DISABLE,
+	EVLIST_CTL_CMD_ACK
+};
+
+int evlist__initialize_ctlfd(struct evlist *evlist, int ctl_fd, int ctl_fd_ack);
+int evlist__finalize_ctlfd(struct evlist *evlist);
+int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd);
+
 #endif /* __PERF_EVLIST_H */
-- 
2.24.1



^ permalink raw reply related	[flat|nested] 49+ messages in thread

* [PATCH v8 04/13] perf stat: factor out body of event handling loop for system wide
  2020-06-17  8:30 [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
                   ` (2 preceding siblings ...)
  2020-06-17  8:36 ` [PATCH v8 03/13] perf evlist: implement control command handling functions Alexey Budankov
@ 2020-06-17  8:37 ` Alexey Budankov
  2020-06-23 14:56   ` Jiri Olsa
  2020-06-17  8:38 ` [PATCH v8 05/13] perf stat: move target check to loop control statement Alexey Budankov
                   ` (9 subsequent siblings)
  13 siblings, 1 reply; 49+ messages in thread
From: Alexey Budankov @ 2020-06-17  8:37 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Jiri Olsa, Namhyung Kim, Alexander Shishkin, Peter Zijlstra,
	Ingo Molnar, Andi Kleen, linux-kernel


Introduce process_timeout() and process_interval() functions that
factor out body of event handling loop for attach and system wide
monitoring use cases.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 tools/perf/builtin-stat.c | 28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 9be020e0098a..31f7ccf9537b 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -475,6 +475,23 @@ static void process_interval(void)
 	print_counters(&rs, 0, NULL);
 }
 
+static bool print_interval(unsigned int interval, int *times)
+{
+	if (interval) {
+		process_interval();
+		if (interval_count && !(--(*times)))
+			return true;
+	}
+	return false;
+}
+
+static bool process_timeout(int timeout, unsigned int interval, int *times)
+{
+	if (timeout)
+		return true;
+	return print_interval(interval, times);
+}
+
 static void enable_counters(void)
 {
 	if (stat_config.initial_delay)
@@ -611,6 +628,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 	struct affinity affinity;
 	int i, cpu;
 	bool second_pass = false;
+	bool stop = false;
 
 	if (interval) {
 		ts.tv_sec  = interval / USEC_PER_MSEC;
@@ -805,17 +823,11 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 			psignal(WTERMSIG(status), argv[0]);
 	} else {
 		enable_counters();
-		while (!done) {
+		while (!done && !stop) {
 			nanosleep(&ts, NULL);
 			if (!is_target_alive(&target, evsel_list->core.threads))
 				break;
-			if (timeout)
-				break;
-			if (interval) {
-				process_interval();
-				if (interval_count && !(--times))
-					break;
-			}
+			stop = process_timeout(timeout, interval, &times);
 		}
 	}
 
-- 
2.24.1



^ permalink raw reply related	[flat|nested] 49+ messages in thread

* [PATCH v8 05/13] perf stat: move target check to loop control statement
  2020-06-17  8:30 [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
                   ` (3 preceding siblings ...)
  2020-06-17  8:37 ` [PATCH v8 04/13] perf stat: factor out body of event handling loop for system wide Alexey Budankov
@ 2020-06-17  8:38 ` Alexey Budankov
  2020-06-17  8:39 ` [PATCH v8 06/13] perf stat: factor out body of event handling loop for fork case Alexey Budankov
                   ` (8 subsequent siblings)
  13 siblings, 0 replies; 49+ messages in thread
From: Alexey Budankov @ 2020-06-17  8:38 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Jiri Olsa, Namhyung Kim, Alexander Shishkin, Peter Zijlstra,
	Ingo Molnar, Andi Kleen, linux-kernel


Check for target existence in loop control statement jointly with 'stop'
indicator based on command line values and external asynchronous 'done'
signal.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 tools/perf/builtin-stat.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 31f7ccf9537b..62bad2df13ba 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -823,10 +823,8 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 			psignal(WTERMSIG(status), argv[0]);
 	} else {
 		enable_counters();
-		while (!done && !stop) {
+		while (!done && !stop && is_target_alive(&target, evsel_list->core.threads)) {
 			nanosleep(&ts, NULL);
-			if (!is_target_alive(&target, evsel_list->core.threads))
-				break;
 			stop = process_timeout(timeout, interval, &times);
 		}
 	}
-- 
2.24.1



^ permalink raw reply related	[flat|nested] 49+ messages in thread

* [PATCH v8 06/13] perf stat: factor out body of event handling loop for fork case
  2020-06-17  8:30 [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
                   ` (4 preceding siblings ...)
  2020-06-17  8:38 ` [PATCH v8 05/13] perf stat: move target check to loop control statement Alexey Budankov
@ 2020-06-17  8:39 ` Alexey Budankov
  2020-06-17  8:40 ` [PATCH v8 07/13] perf stat: factor out event handling loop into dispatch_events() Alexey Budankov
                   ` (7 subsequent siblings)
  13 siblings, 0 replies; 49+ messages in thread
From: Alexey Budankov @ 2020-06-17  8:39 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Jiri Olsa, Namhyung Kim, Alexander Shishkin, Peter Zijlstra,
	Ingo Molnar, Andi Kleen, linux-kernel


Factor out body of event handling loop for fork case reusing
process_timeout() and process_interval() functions.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 tools/perf/builtin-stat.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 62bad2df13ba..3bc538576607 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -798,13 +798,9 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 		enable_counters();
 
 		if (interval || timeout) {
-			while (!waitpid(child_pid, &status, WNOHANG)) {
+			while (!stop && !waitpid(child_pid, &status, WNOHANG)) {
 				nanosleep(&ts, NULL);
-				if (timeout)
-					break;
-				process_interval();
-				if (interval_count && !(--times))
-					break;
+				stop = process_timeout(timeout, interval, &times);
 			}
 		}
 		if (child_pid != -1) {
-- 
2.24.1



^ permalink raw reply related	[flat|nested] 49+ messages in thread

* [PATCH v8 07/13] perf stat: factor out event handling loop into dispatch_events()
  2020-06-17  8:30 [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
                   ` (5 preceding siblings ...)
  2020-06-17  8:39 ` [PATCH v8 06/13] perf stat: factor out body of event handling loop for fork case Alexey Budankov
@ 2020-06-17  8:40 ` Alexey Budankov
  2020-06-23 14:56   ` Jiri Olsa
  2020-06-17  8:40 ` [PATCH v8 08/13] perf stat: extend -D,--delay option with -1 value Alexey Budankov
                   ` (6 subsequent siblings)
  13 siblings, 1 reply; 49+ messages in thread
From: Alexey Budankov @ 2020-06-17  8:40 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Jiri Olsa, Namhyung Kim, Alexander Shishkin, Peter Zijlstra,
	Ingo Molnar, Andi Kleen, linux-kernel


Consolidate event dispatching loops for fork, attach and system
wide monitoring use cases into common dispatch_events() function.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 tools/perf/builtin-stat.c | 35 ++++++++++++++++++++++++-----------
 1 file changed, 24 insertions(+), 11 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 3bc538576607..39749c290508 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -557,6 +557,27 @@ static bool is_target_alive(struct target *_target,
 	return false;
 }
 
+static int dispatch_events(bool forks, int timeout, int interval, int *times, struct timespec *ts)
+{
+	bool stop = false;
+	int child = 0, status = 0;
+
+	while (1) {
+		if (forks)
+			child = waitpid(child_pid, &status, WNOHANG);
+		else
+			child = !is_target_alive(&target, evsel_list->core.threads) ? 1 : 0;
+
+		if (done || stop || child)
+			break;
+
+		nanosleep(ts, NULL);
+		stop = process_timeout(timeout, interval, times);
+	}
+
+	return status;
+}
+
 enum counter_recovery {
 	COUNTER_SKIP,
 	COUNTER_RETRY,
@@ -628,7 +649,6 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 	struct affinity affinity;
 	int i, cpu;
 	bool second_pass = false;
-	bool stop = false;
 
 	if (interval) {
 		ts.tv_sec  = interval / USEC_PER_MSEC;
@@ -797,12 +817,8 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 		perf_evlist__start_workload(evsel_list);
 		enable_counters();
 
-		if (interval || timeout) {
-			while (!stop && !waitpid(child_pid, &status, WNOHANG)) {
-				nanosleep(&ts, NULL);
-				stop = process_timeout(timeout, interval, &times);
-			}
-		}
+		if (interval || timeout)
+			status = dispatch_events(forks, timeout, interval, &times, &ts);
 		if (child_pid != -1) {
 			if (timeout)
 				kill(child_pid, SIGTERM);
@@ -819,10 +835,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 			psignal(WTERMSIG(status), argv[0]);
 	} else {
 		enable_counters();
-		while (!done && !stop && is_target_alive(&target, evsel_list->core.threads)) {
-			nanosleep(&ts, NULL);
-			stop = process_timeout(timeout, interval, &times);
-		}
+		dispatch_events(forks, timeout, interval, &times, &ts);
 	}
 
 	disable_counters();
-- 
2.24.1



^ permalink raw reply related	[flat|nested] 49+ messages in thread

* [PATCH v8 08/13] perf stat: extend -D,--delay option with -1 value
  2020-06-17  8:30 [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
                   ` (6 preceding siblings ...)
  2020-06-17  8:40 ` [PATCH v8 07/13] perf stat: factor out event handling loop into dispatch_events() Alexey Budankov
@ 2020-06-17  8:40 ` Alexey Budankov
  2020-06-17  8:41 ` [PATCH v8 09/13] perf stat: implement control commands handling Alexey Budankov
                   ` (5 subsequent siblings)
  13 siblings, 0 replies; 49+ messages in thread
From: Alexey Budankov @ 2020-06-17  8:40 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Jiri Olsa, Namhyung Kim, Alexander Shishkin, Peter Zijlstra,
	Ingo Molnar, Andi Kleen, linux-kernel


Extend -D,--delay option with -1 value to start monitoring with
events disabled to be enabled later by enable command provided
via control file descriptor.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 tools/perf/Documentation/perf-stat.txt |  5 +++--
 tools/perf/builtin-stat.c              | 18 ++++++++++++++----
 tools/perf/util/evlist.h               |  3 +++
 tools/perf/util/stat.h                 |  2 +-
 4 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index b029ee728a0b..9f32f6cd558d 100644
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -238,8 +238,9 @@ mode, use --per-node in addition to -a. (system-wide).
 
 -D msecs::
 --delay msecs::
-After starting the program, wait msecs before measuring. This is useful to
-filter out the startup phase of the program, which is often very different.
+After starting the program, wait msecs before measuring (-1: start with events
+disabled). This is useful to filter out the startup phase of the program,
+which is often very different.
 
 -T::
 --transaction::
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 39749c290508..f88d5ee55022 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -494,16 +494,26 @@ static bool process_timeout(int timeout, unsigned int interval, int *times)
 
 static void enable_counters(void)
 {
-	if (stat_config.initial_delay)
+	if (stat_config.initial_delay < 0) {
+		pr_info(EVLIST_DISABLED_MSG);
+		return;
+	}
+
+	if (stat_config.initial_delay > 0) {
+		pr_info(EVLIST_DISABLED_MSG);
 		usleep(stat_config.initial_delay * USEC_PER_MSEC);
+	}
 
 	/*
 	 * We need to enable counters only if:
 	 * - we don't have tracee (attaching to task or cpu)
 	 * - we have initial delay configured
 	 */
-	if (!target__none(&target) || stat_config.initial_delay)
+	if (!target__none(&target) || stat_config.initial_delay) {
 		evlist__enable(evsel_list);
+		if (stat_config.initial_delay > 0)
+			pr_info(EVLIST_ENABLED_MSG);
+	}
 }
 
 static void disable_counters(void)
@@ -1060,8 +1070,8 @@ static struct option stat_options[] = {
 		     "aggregate counts per thread", AGGR_THREAD),
 	OPT_SET_UINT(0, "per-node", &stat_config.aggr_mode,
 		     "aggregate counts per numa node", AGGR_NODE),
-	OPT_UINTEGER('D', "delay", &stat_config.initial_delay,
-		     "ms to wait before starting measurement after program start"),
+	OPT_INTEGER('D', "delay", &stat_config.initial_delay,
+		    "ms to wait before starting measurement after program start (-1: start with events disabled)"),
 	OPT_CALLBACK_NOOPT(0, "metric-only", &stat_config.metric_only, NULL,
 			"Only print computed metrics. No raw values", enable_metric_only),
 	OPT_BOOLEAN(0, "metric-no-group", &stat_config.metric_no_group,
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index bccf0a970371..7c3726a685f5 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -377,4 +377,7 @@ int evlist__initialize_ctlfd(struct evlist *evlist, int ctl_fd, int ctl_fd_ack);
 int evlist__finalize_ctlfd(struct evlist *evlist);
 int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd);
 
+#define EVLIST_ENABLED_MSG "Events enabled\n"
+#define EVLIST_DISABLED_MSG "Events disabled\n"
+
 #endif /* __PERF_EVLIST_H */
diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
index f75ae679eb28..626421ef35c2 100644
--- a/tools/perf/util/stat.h
+++ b/tools/perf/util/stat.h
@@ -116,7 +116,7 @@ struct perf_stat_config {
 	FILE			*output;
 	unsigned int		 interval;
 	unsigned int		 timeout;
-	unsigned int		 initial_delay;
+	int			 initial_delay;
 	unsigned int		 unit_width;
 	unsigned int		 metric_only_len;
 	int			 times;
-- 
2.24.1



^ permalink raw reply related	[flat|nested] 49+ messages in thread

* [PATCH v8 09/13] perf stat: implement control commands handling
  2020-06-17  8:30 [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
                   ` (7 preceding siblings ...)
  2020-06-17  8:40 ` [PATCH v8 08/13] perf stat: extend -D,--delay option with -1 value Alexey Budankov
@ 2020-06-17  8:41 ` Alexey Budankov
  2020-06-23 14:54   ` Jiri Olsa
  2020-06-23 14:54   ` Jiri Olsa
  2020-06-17  8:42 ` [PATCH v8 10/13] perf stat: introduce --control fd:ctl-fd[,ack-fd] options Alexey Budankov
                   ` (4 subsequent siblings)
  13 siblings, 2 replies; 49+ messages in thread
From: Alexey Budankov @ 2020-06-17  8:41 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Jiri Olsa, Namhyung Kim, Alexander Shishkin, Peter Zijlstra,
	Ingo Molnar, Andi Kleen, linux-kernel


Implement handling of 'enable' and 'disable' control commands
coming from control file descriptor. process_evlist() function
checks for events on control fds and makes required operations.
If poll event splits initiated timeout interval then the reminder
is calculated and still waited in the following poll() syscall.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 tools/perf/builtin-stat.c | 67 +++++++++++++++++++++++++++++----------
 1 file changed, 50 insertions(+), 17 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index f88d5ee55022..cc56d71a3ed5 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -492,6 +492,31 @@ static bool process_timeout(int timeout, unsigned int interval, int *times)
 	return print_interval(interval, times);
 }
 
+static bool process_evlist(struct evlist *evlist, unsigned int interval, int *times)
+{
+	bool stop = false;
+	enum evlist_ctl_cmd cmd = EVLIST_CTL_CMD_UNSUPPORTED;
+
+	if (evlist__ctlfd_process(evlist, &cmd) > 0) {
+		switch (cmd) {
+		case EVLIST_CTL_CMD_ENABLE:
+			pr_info(EVLIST_ENABLED_MSG);
+			stop = print_interval(interval, times);
+			break;
+		case EVLIST_CTL_CMD_DISABLE:
+			stop = print_interval(interval, times);
+			pr_info(EVLIST_DISABLED_MSG);
+			break;
+		case EVLIST_CTL_CMD_ACK:
+		case EVLIST_CTL_CMD_UNSUPPORTED:
+		default:
+			break;
+		}
+	}
+
+	return stop;
+}
+
 static void enable_counters(void)
 {
 	if (stat_config.initial_delay < 0) {
@@ -567,10 +592,21 @@ static bool is_target_alive(struct target *_target,
 	return false;
 }
 
-static int dispatch_events(bool forks, int timeout, int interval, int *times, struct timespec *ts)
+static int dispatch_events(bool forks, int timeout, int interval, int *times)
 {
 	bool stop = false;
 	int child = 0, status = 0;
+	int time_to_sleep, sleep_time;
+	struct timespec time_start, time_stop, time_diff;
+
+	if (interval)
+		sleep_time = interval;
+	else if (timeout)
+		sleep_time = timeout;
+	else
+		sleep_time = 1000;
+
+	time_to_sleep = sleep_time;
 
 	while (1) {
 		if (forks)
@@ -581,8 +617,17 @@ static int dispatch_events(bool forks, int timeout, int interval, int *times, st
 		if (done || stop || child)
 			break;
 
-		nanosleep(ts, NULL);
-		stop = process_timeout(timeout, interval, times);
+		clock_gettime(CLOCK_MONOTONIC, &time_start);
+		if (!(evlist__poll(evsel_list, time_to_sleep) > 0)) { /* poll timeout or EINTR */
+			stop = process_timeout(timeout, interval, times);
+			time_to_sleep = sleep_time;
+		} else { /* fd revent */
+			stop = process_evlist(evsel_list, interval, times);
+			clock_gettime(CLOCK_MONOTONIC, &time_stop);
+			diff_timespec(&time_diff, &time_stop, &time_start);
+			time_to_sleep -= time_diff.tv_sec * MSEC_PER_SEC +
+					time_diff.tv_nsec / NSEC_PER_MSEC;
+		}
 	}
 
 	return status;
@@ -651,7 +696,6 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 	char msg[BUFSIZ];
 	unsigned long long t0, t1;
 	struct evsel *counter;
-	struct timespec ts;
 	size_t l;
 	int status = 0;
 	const bool forks = (argc > 0);
@@ -660,17 +704,6 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 	int i, cpu;
 	bool second_pass = false;
 
-	if (interval) {
-		ts.tv_sec  = interval / USEC_PER_MSEC;
-		ts.tv_nsec = (interval % USEC_PER_MSEC) * NSEC_PER_MSEC;
-	} else if (timeout) {
-		ts.tv_sec  = timeout / USEC_PER_MSEC;
-		ts.tv_nsec = (timeout % USEC_PER_MSEC) * NSEC_PER_MSEC;
-	} else {
-		ts.tv_sec  = 1;
-		ts.tv_nsec = 0;
-	}
-
 	if (forks) {
 		if (perf_evlist__prepare_workload(evsel_list, &target, argv, is_pipe,
 						  workload_exec_failed_signal) < 0) {
@@ -828,7 +861,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 		enable_counters();
 
 		if (interval || timeout)
-			status = dispatch_events(forks, timeout, interval, &times, &ts);
+			status = dispatch_events(forks, timeout, interval, &times);
 		if (child_pid != -1) {
 			if (timeout)
 				kill(child_pid, SIGTERM);
@@ -845,7 +878,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 			psignal(WTERMSIG(status), argv[0]);
 	} else {
 		enable_counters();
-		dispatch_events(forks, timeout, interval, &times, &ts);
+		dispatch_events(forks, timeout, interval, &times);
 	}
 
 	disable_counters();
-- 
2.24.1



^ permalink raw reply related	[flat|nested] 49+ messages in thread

* [PATCH v8 10/13] perf stat: introduce --control fd:ctl-fd[,ack-fd] options
  2020-06-17  8:30 [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
                   ` (8 preceding siblings ...)
  2020-06-17  8:41 ` [PATCH v8 09/13] perf stat: implement control commands handling Alexey Budankov
@ 2020-06-17  8:42 ` Alexey Budankov
  2020-06-17  8:42 ` [PATCH v8 11/13] perf record: extend -D,--delay option with -1 value Alexey Budankov
                   ` (3 subsequent siblings)
  13 siblings, 0 replies; 49+ messages in thread
From: Alexey Budankov @ 2020-06-17  8:42 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Jiri Olsa, Namhyung Kim, Alexander Shishkin, Peter Zijlstra,
	Ingo Molnar, Andi Kleen, linux-kernel


Introduce --control fd:ctl-fd[,ack-fd] options to pass open file
descriptors numbers from command line. Extend perf-stat.txt file
with --control fd:ctl-fd[,ack-fd] options description. Document
possible usage model introduced by --control fd:ctl-fd[,ack-fd]
options by providing example bash shell script.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 tools/perf/Documentation/perf-stat.txt | 39 ++++++++++++++++++++++++++
 tools/perf/builtin-stat.c              | 38 +++++++++++++++++++++++++
 tools/perf/util/stat.h                 |  2 ++
 3 files changed, 79 insertions(+)

diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 9f32f6cd558d..c9bfefc051fb 100644
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -176,6 +176,45 @@ with it.  --append may be used here.  Examples:
      3>results  perf stat --log-fd 3          -- $cmd
      3>>results perf stat --log-fd 3 --append -- $cmd
 
+--control fd:ctl-fd[,ack-fd]
+Listen on ctl-fd descriptor for command to control measurement ('enable': enable events,
+'disable': disable events). Measurements can be started with events disabled using
+--delay=-1 option. Optionally send control command completion ('ack\n') to ack-fd descriptor
+to synchronize with the controlling process. Example of bash shell script to enable and
+disable events during measurements:
+
+#!/bin/bash
+
+ctl_dir=/tmp/
+
+ctl_fifo=${ctl_dir}perf_ctl.fifo
+test -p ${ctl_fifo} && unlink ${ctl_fifo}
+mkfifo ${ctl_fifo}
+exec {ctl_fd}<>${ctl_fifo}
+
+ctl_ack_fifo=${ctl_dir}perf_ctl_ack.fifo
+test -p ${ctl_ack_fifo} && unlink ${ctl_ack_fifo}
+mkfifo ${ctl_ack_fifo}
+exec {ctl_fd_ack}<>${ctl_ack_fifo}
+
+perf stat -D -1 -e cpu-cycles -a -I 1000       \
+          --control fd:${ctl_fd},${ctl_fd_ack} \
+          -- sleep 30 &
+perf_pid=$!
+
+sleep 5  && echo 'enable' >&${ctl_fd} && read -u ${ctl_fd_ack} e1 && echo "enabled(${e1})"
+sleep 10 && echo 'disable' >&${ctl_fd} && read -u ${ctl_fd_ack} d1 && echo "disabled(${d1})"
+
+exec {ctl_fd_ack}>&-
+unlink ${ctl_ack_fifo}
+
+exec {ctl_fd}>&-
+unlink ${ctl_fifo}
+
+wait -n ${perf_pid}
+exit $?
+
+
 --pre::
 --post::
 	Pre and post measurement hooks, e.g.:
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index cc56d71a3ed5..4cb29b40b860 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -188,6 +188,8 @@ static struct perf_stat_config stat_config = {
 	.metric_only_len	= METRIC_ONLY_LEN,
 	.walltime_nsecs_stats	= &walltime_nsecs_stats,
 	.big_num		= true,
+	.ctl_fd			= -1,
+	.ctl_fd_ack		= -1
 };
 
 static bool cpus_map_matched(struct evsel *a, struct evsel *b)
@@ -1032,6 +1034,33 @@ static int parse_metric_groups(const struct option *opt,
 					 &stat_config.metric_events);
 }
 
+static int parse_control_option(const struct option *opt,
+				const char *str,
+				int unset __maybe_unused)
+{
+	char *comma = NULL, *endptr = NULL;
+	struct perf_stat_config *config = (struct perf_stat_config *)opt->value;
+
+	if (strncmp(str, "fd:", 3))
+		return -EINVAL;
+
+	config->ctl_fd = strtoul(&str[3], &endptr, 0);
+	if (endptr == &str[3])
+		return -EINVAL;
+
+	comma = strchr(str, ',');
+	if (comma) {
+		if (endptr != comma)
+			return -EINVAL;
+
+		config->ctl_fd_ack = strtoul(comma + 1, &endptr, 0);
+		if (endptr == comma + 1 || *endptr != '\0')
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
 static struct option stat_options[] = {
 	OPT_BOOLEAN('T', "transaction", &transaction_run,
 		    "hardware transaction statistics"),
@@ -1133,6 +1162,10 @@ static struct option stat_options[] = {
 		"libpfm4 event selector. use 'perf list' to list available events",
 		parse_libpfm_events_option),
 #endif
+	OPT_CALLBACK(0, "control", &stat_config, "fd:ctl-fd[,ack-fd]",
+		     "Listen on ctl-fd descriptor for command to control measurement ('enable': enable events, 'disable': disable events).\n"
+		     "\t\t\t  Optionally send control command completion ('ack\\n') to ack-fd descriptor.",
+		      parse_control_option),
 	OPT_END()
 };
 
@@ -2304,6 +2337,9 @@ int cmd_stat(int argc, const char **argv)
 	signal(SIGALRM, skip_signal);
 	signal(SIGABRT, skip_signal);
 
+	if (evlist__initialize_ctlfd(evsel_list, stat_config.ctl_fd, stat_config.ctl_fd_ack))
+		goto out;
+
 	status = 0;
 	for (run_idx = 0; forever || run_idx < stat_config.run_count; run_idx++) {
 		if (stat_config.run_count != 1 && verbose > 0)
@@ -2323,6 +2359,8 @@ int cmd_stat(int argc, const char **argv)
 	if (!forever && status != -1 && (!interval || stat_config.summary))
 		print_counters(NULL, argc, argv);
 
+	evlist__finalize_ctlfd(evsel_list);
+
 	if (STAT_RECORD) {
 		/*
 		 * We synthesize the kernel mmap record just so that older tools
diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
index 626421ef35c2..06f0baabe775 100644
--- a/tools/perf/util/stat.h
+++ b/tools/perf/util/stat.h
@@ -133,6 +133,8 @@ struct perf_stat_config {
 	struct perf_cpu_map		*cpus_aggr_map;
 	u64			*walltime_run;
 	struct rblist		 metric_events;
+	int			 ctl_fd;
+	int			 ctl_fd_ack;
 };
 
 void perf_stat__set_big_num(int set);
-- 
2.24.1



^ permalink raw reply related	[flat|nested] 49+ messages in thread

* [PATCH v8 11/13] perf record: extend -D,--delay option with -1 value
  2020-06-17  8:30 [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
                   ` (9 preceding siblings ...)
  2020-06-17  8:42 ` [PATCH v8 10/13] perf stat: introduce --control fd:ctl-fd[,ack-fd] options Alexey Budankov
@ 2020-06-17  8:42 ` Alexey Budankov
  2020-06-17  8:43 ` [PATCH v8 12/13] perf record: implement control commands handling Alexey Budankov
                   ` (2 subsequent siblings)
  13 siblings, 0 replies; 49+ messages in thread
From: Alexey Budankov @ 2020-06-17  8:42 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Jiri Olsa, Namhyung Kim, Alexander Shishkin, Peter Zijlstra,
	Ingo Molnar, Andi Kleen, linux-kernel


Extend -D,--delay option with -1 to start collection with events
disabled to be enabled later by 'enable' command provided via
control file descriptor.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 tools/perf/Documentation/perf-record.txt |  5 +++--
 tools/perf/builtin-record.c              | 12 ++++++++----
 tools/perf/builtin-trace.c               |  2 +-
 tools/perf/util/record.h                 |  2 +-
 4 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index fa8a5fcd27ab..a84376605805 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -407,8 +407,9 @@ if combined with -a or -C options.
 
 -D::
 --delay=::
-After starting the program, wait msecs before measuring. This is useful to
-filter out the startup phase of the program, which is often very different.
+After starting the program, wait msecs before measuring (-1: start with events
+disabled). This is useful to filter out the startup phase of the program, which
+is often very different.
 
 -I::
 --intr-regs::
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index e108d90ae2ed..d0b29a1070a0 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1749,8 +1749,12 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 	}
 
 	if (opts->initial_delay) {
-		usleep(opts->initial_delay * USEC_PER_MSEC);
-		evlist__enable(rec->evlist);
+		pr_info(EVLIST_DISABLED_MSG);
+		if (opts->initial_delay > 0) {
+			usleep(opts->initial_delay * USEC_PER_MSEC);
+			evlist__enable(rec->evlist);
+			pr_info(EVLIST_ENABLED_MSG);
+		}
 	}
 
 	trigger_ready(&auxtrace_snapshot_trigger);
@@ -2462,8 +2466,8 @@ static struct option __record_options[] = {
 	OPT_CALLBACK('G', "cgroup", &record.evlist, "name",
 		     "monitor event in cgroup name only",
 		     parse_cgroups),
-	OPT_UINTEGER('D', "delay", &record.opts.initial_delay,
-		  "ms to wait before starting measurement after program start"),
+	OPT_INTEGER('D', "delay", &record.opts.initial_delay,
+		  "ms to wait before starting measurement after program start (-1: start with events disabled)"),
 	OPT_BOOLEAN(0, "kcore", &record.opts.kcore, "copy /proc/kcore"),
 	OPT_STRING('u', "uid", &record.opts.target.uid_str, "user",
 		   "user to profile"),
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 4cbb64edc998..290149b1b3b5 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -4813,7 +4813,7 @@ int cmd_trace(int argc, const char **argv)
 			"per thread proc mmap processing timeout in ms"),
 	OPT_CALLBACK('G', "cgroup", &trace, "name", "monitor event in cgroup name only",
 		     trace__parse_cgroups),
-	OPT_UINTEGER('D', "delay", &trace.opts.initial_delay,
+	OPT_INTEGER('D', "delay", &trace.opts.initial_delay,
 		     "ms to wait before starting measurement after program "
 		     "start"),
 	OPTS_EVSWITCH(&trace.evswitch),
diff --git a/tools/perf/util/record.h b/tools/perf/util/record.h
index 39d1de4b2a36..da138dcb4d34 100644
--- a/tools/perf/util/record.h
+++ b/tools/perf/util/record.h
@@ -61,7 +61,7 @@ struct record_opts {
 	const char    *auxtrace_snapshot_opts;
 	const char    *auxtrace_sample_opts;
 	bool	      sample_transaction;
-	unsigned      initial_delay;
+	int	      initial_delay;
 	bool	      use_clockid;
 	clockid_t     clockid;
 	u64	      clockid_res_ns;
-- 
2.24.1



^ permalink raw reply related	[flat|nested] 49+ messages in thread

* [PATCH v8 12/13] perf record: implement control commands handling
  2020-06-17  8:30 [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
                   ` (10 preceding siblings ...)
  2020-06-17  8:42 ` [PATCH v8 11/13] perf record: extend -D,--delay option with -1 value Alexey Budankov
@ 2020-06-17  8:43 ` Alexey Budankov
  2020-06-23 14:54   ` Jiri Olsa
  2020-06-17  8:44 ` [PATCH v8 13/13] perf record: introduce --control fd:ctl-fd[,ack-fd] options Alexey Budankov
  2020-06-22  3:38 ` [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
  13 siblings, 1 reply; 49+ messages in thread
From: Alexey Budankov @ 2020-06-17  8:43 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Jiri Olsa, Namhyung Kim, Alexander Shishkin, Peter Zijlstra,
	Ingo Molnar, Andi Kleen, linux-kernel


Implement handling of 'enable' and 'disable' control commands
coming from control file descriptor.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 tools/perf/builtin-record.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index d0b29a1070a0..0394e068dde8 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1527,6 +1527,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 	bool disabled = false, draining = false;
 	int fd;
 	float ratio = 0;
+	enum evlist_ctl_cmd cmd = EVLIST_CTL_CMD_UNSUPPORTED;
 
 	atexit(record__sig_exit);
 	signal(SIGCHLD, sig_handler);
@@ -1830,6 +1831,21 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 				alarm(rec->switch_output.time);
 		}
 
+		if (evlist__ctlfd_process(rec->evlist, &cmd) > 0) {
+			switch (cmd) {
+			case EVLIST_CTL_CMD_ENABLE:
+				pr_info(EVLIST_ENABLED_MSG);
+				break;
+			case EVLIST_CTL_CMD_DISABLE:
+				pr_info(EVLIST_DISABLED_MSG);
+				break;
+			case EVLIST_CTL_CMD_ACK:
+			case EVLIST_CTL_CMD_UNSUPPORTED:
+			default:
+				break;
+			}
+		}
+
 		if (hits == rec->samples) {
 			if (done || draining)
 				break;
-- 
2.24.1



^ permalink raw reply related	[flat|nested] 49+ messages in thread

* [PATCH v8 13/13] perf record: introduce --control fd:ctl-fd[,ack-fd] options
  2020-06-17  8:30 [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
                   ` (11 preceding siblings ...)
  2020-06-17  8:43 ` [PATCH v8 12/13] perf record: implement control commands handling Alexey Budankov
@ 2020-06-17  8:44 ` Alexey Budankov
  2020-06-22  3:38 ` [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
  13 siblings, 0 replies; 49+ messages in thread
From: Alexey Budankov @ 2020-06-17  8:44 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Jiri Olsa, Namhyung Kim, Alexander Shishkin, Peter Zijlstra,
	Ingo Molnar, Andi Kleen, linux-kernel


Introduce --control fd:ctl-fd[,ack-fd] options to pass open file
descriptors numbers from command line. Extend perf-record.txt file
with --control fd:ctl-fd[,ack-fd] options description. Document
possible usage model introduced by --control fd:ctl-fd[,ack-fd]
options by providing example bash shell script.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 tools/perf/Documentation/perf-record.txt | 39 ++++++++++++++++++++++++
 tools/perf/builtin-record.c              | 37 ++++++++++++++++++++++
 tools/perf/util/record.h                 |  2 ++
 3 files changed, 78 insertions(+)

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index a84376605805..3f72d8e261f3 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -627,6 +627,45 @@ option. The -e option and this one can be mixed and matched.  Events
 can be grouped using the {} notation.
 endif::HAVE_LIBPFM[]
 
+--control fd:ctl-fd[,ack-fd]
+Listen on ctl-fd descriptor for command to control measurement ('enable': enable events,
+'disable': disable events). Measurements can be started with events disabled using
+--delay=-1 option. Optionally send control command completion ('ack\n') to ack-fd descriptor
+to synchronize with the controlling process. Example of bash shell script to enable and
+disable events during measurements:
+
+#!/bin/bash
+
+ctl_dir=/tmp/
+
+ctl_fifo=${ctl_dir}perf_ctl.fifo
+test -p ${ctl_fifo} && unlink ${ctl_fifo}
+mkfifo ${ctl_fifo}
+exec {ctl_fd}<>${ctl_fifo}
+
+ctl_ack_fifo=${ctl_dir}perf_ctl_ack.fifo
+test -p ${ctl_ack_fifo} && unlink ${ctl_ack_fifo}
+mkfifo ${ctl_ack_fifo}
+exec {ctl_fd_ack}<>${ctl_ack_fifo}
+
+perf record -D -1 -e cpu-cycles -a               \
+            --control fd:${ctl_fd},${ctl_fd_ack} \
+            -- sleep 30 &
+perf_pid=$!
+
+sleep 5  && echo 'enable' >&${ctl_fd} && read -u ${ctl_fd_ack} e1 && echo "enabled(${e1})"
+sleep 10 && echo 'disable' >&${ctl_fd} && read -u ${ctl_fd_ack} d1 && echo "disabled(${d1})"
+
+exec {ctl_fd_ack}>&-
+unlink ${ctl_ack_fifo}
+
+exec {ctl_fd}>&-
+unlink ${ctl_fifo}
+
+wait -n ${perf_pid}
+exit $?
+
+
 SEE ALSO
 --------
 linkperf:perf-stat[1], linkperf:perf-list[1], linkperf:perf-intel-pt[1]
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 0394e068dde8..5492c7dd3ac5 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1749,6 +1749,9 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 		perf_evlist__start_workload(rec->evlist);
 	}
 
+	if (evlist__initialize_ctlfd(rec->evlist, opts->ctl_fd, opts->ctl_fd_ack))
+		goto out_child;
+
 	if (opts->initial_delay) {
 		pr_info(EVLIST_DISABLED_MSG);
 		if (opts->initial_delay > 0) {
@@ -1895,6 +1898,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 		record__synthesize_workload(rec, true);
 
 out_child:
+	evlist__finalize_ctlfd(rec->evlist);
 	record__mmap_read_all(rec, true);
 	record__aio_mmap_read_sync(rec);
 
@@ -2244,6 +2248,33 @@ static int record__parse_mmap_pages(const struct option *opt,
 	return ret;
 }
 
+static int parse_control_option(const struct option *opt,
+				const char *str,
+				int unset __maybe_unused)
+{
+	char *comma = NULL, *endptr = NULL;
+	struct record_opts *config = (struct record_opts *)opt->value;
+
+	if (strncmp(str, "fd:", 3))
+		return -EINVAL;
+
+	config->ctl_fd = strtoul(&str[3], &endptr, 0);
+	if (endptr == &str[3])
+		return -EINVAL;
+
+	comma = strchr(str, ',');
+	if (comma) {
+		if (endptr != comma)
+			return -EINVAL;
+
+		config->ctl_fd_ack = strtoul(comma + 1, &endptr, 0);
+		if (endptr == comma + 1 || *endptr != '\0')
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
 static void switch_output_size_warn(struct record *rec)
 {
 	u64 wakeup_size = evlist__mmap_size(rec->opts.mmap_pages);
@@ -2380,6 +2411,8 @@ static struct record record = {
 		},
 		.mmap_flush          = MMAP_FLUSH_DEFAULT,
 		.nr_threads_synthesize = 1,
+		.ctl_fd              = -1,
+		.ctl_fd_ack          = -1,
 	},
 	.tool = {
 		.sample		= process_sample_event,
@@ -2581,6 +2614,10 @@ static struct option __record_options[] = {
 		"libpfm4 event selector. use 'perf list' to list available events",
 		parse_libpfm_events_option),
 #endif
+	OPT_CALLBACK(0, "control", &record.opts, "fd:ctl-fd[,ack-fd]",
+		     "Listen on ctl-fd descriptor for command to control measurement ('enable': enable events, 'disable': disable events).\n"
+		     "\t\t\t  Optionally send control command completion ('ack\\n') to ack-fd descriptor.",
+		      parse_control_option),
 	OPT_END()
 };
 
diff --git a/tools/perf/util/record.h b/tools/perf/util/record.h
index da138dcb4d34..4cb72a478af1 100644
--- a/tools/perf/util/record.h
+++ b/tools/perf/util/record.h
@@ -70,6 +70,8 @@ struct record_opts {
 	int	      mmap_flush;
 	unsigned int  comp_level;
 	unsigned int  nr_threads_synthesize;
+	int	      ctl_fd;
+	int	      ctl_fd_ack;
 };
 
 extern const char * const *record_usage;
-- 
2.24.1



^ permalink raw reply related	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes
  2020-06-17  8:30 [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
                   ` (12 preceding siblings ...)
  2020-06-17  8:44 ` [PATCH v8 13/13] perf record: introduce --control fd:ctl-fd[,ack-fd] options Alexey Budankov
@ 2020-06-22  3:38 ` Alexey Budankov
  2020-06-22  8:55   ` Jiri Olsa
  13 siblings, 1 reply; 49+ messages in thread
From: Alexey Budankov @ 2020-06-22  3:38 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo, Jiri Olsa
  Cc: Namhyung Kim, Alexander Shishkin, Peter Zijlstra, Ingo Molnar,
	Andi Kleen, linux-kernel


Hi,

On 17.06.2020 11:30, Alexey Budankov wrote:
> 
> Changes in v8:
> - avoided moving of fds at fdarray__filter() call
> - skipped counting of fds with zeroed revents at fdarray__filter() call
> - converted explicit --ctl-fd[-ack] into --control fd:ctl-fd[,ack-fd option 
> - updated docs to accommodate --control fd:ctl-fd[,ack-fd] option

Are there any questions or thoughts so far?

Thanks,
Alexey

> 
> v7: https://lore.kernel.org/lkml/5de4b954-24f0-1e8d-5a0d-7b12783b8218@linux.intel.com/
> 
> Changes in v7:
> - added missing perf-record.txt changes 
> - adjusted docs wording for --ctl-fd,ctl-fd-ack options 
>   to additionally mention --delay=-1 effect
> 
> v6: https://lore.kernel.org/lkml/f8e3a714-d9b1-4647-e1d2-9981cbaa83ec@linux.intel.com/
> 
> Changes in v6:
> - split re-factoring of events handling loops for stat mode
>   into smaller incremental parts
> - added parts missing at v5
> - corrected v5 runtime issues
> 
> v5: https://lore.kernel.org/lkml/e5cac8dd-7aa4-ec7c-671c-07756907acba@linux.intel.com/
> 
> Changes in v5:
> - split re-factoring of events handling loops for stat mode
>   into smaller incremental parts
> 
> v4: https://lore.kernel.org/lkml/653fe5f3-c986-a841-1ed8-0a7d2fa24c00@linux.intel.com/
> 
> Changes in v4:
> - made checking of ctlfd state unconditional in record trace streaming loop
> - introduced static poll fds to keep evlist__filter_pollfd() unaffected
> - handled ret code of evlist__initialize_ctlfd() where need
> - renamed and structured handle_events() function
> - applied anonymous structs where needed
> 
> v3: https://lore.kernel.org/lkml/eb38e9e5-754f-d410-1d9b-e26b702d51b7@linux.intel.com/
> 
> Changes in v3:
> - renamed functions and types from perf_evlist_ to evlist_ to avoid
>   clash with libperf code;
> - extended commands to be strings of variable length consisting of
>   command name and also possibly including command specific data;
> - merged docs update with the code changes;
> - updated docs for -D,--delay=-1 option for stat and record modes;
> 
> v2: https://lore.kernel.org/lkml/d582cc3d-2302-c7e2-70d3-bc7ab6f628c3@linux.intel.com/
> 
> Changes in v2:
> - renamed resume and pause commands to enable and disable ones, renamed
>   CTL_CMD_RESUME and CTL_CMD_PAUSE to CTL_CMD_ENABLE and CTL_CMD_DISABLE
>   to fit to the appropriate ioctls and avoid mixing up with PAUSE_OUTPUT
>   ioctl;
> - factored out event handling loop into a handle_events() for stat mode;
> - separated -D,--delay=-1 into separate patches for stat and record modes;
> 
> v1: https://lore.kernel.org/lkml/825a5132-b58d-c0b6-b050-5a6040386ec7@linux.intel.com/
> 
> repo: tip of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git perf/core
> 
> The patch set implements handling of 'start disabled', 'enable' and 'disable'
> external control commands which can be provided for stat and record modes
> of the tool from an external controlling process. 'start disabled' command
> can be used to postpone enabling of events in the beginning of a monitoring
> session. 'enable' and 'disable' commands can be used to enable and disable
> events correspondingly any time after the start of the session.
> 
> The 'start disabled', 'enable' and 'disable' external control commands can be
> used to focus measurement on specially selected time intervals of workload
> execution. Focused measurement reduces tool intrusion and influence on
> workload behavior, reduces distortion and amount of collected and stored
> data, mitigates data accuracy loss because measurement and data capturing
> happen only during intervals of interest.
> 
> A controlling process can be a bash shell script [1], native executable or
> any other language program that can directly work with file descriptors,
> e.g. pipes [2], and spawn a process, specially the tool one.
> 
> -D,--delay <val> option is extended with -1 value to skip events enabling
> in the beginning of a monitoring session ('start disabled' command).
> --control fd:ctl-fd[,ack-fd] command line option is introduced to provide the
> tool with a pair of file descriptors to listen to control commands and reply
> to the controlling process on the completion of received commands.
> 
> The tool reads control command message from ctl-fd descriptor, handles the
> command and optionally replies acknowledgement message to ack-fd descriptor,
> if it is specified on the command line. 'enable' command is recognized as
> 'enable' string message and 'disable' command is recognized as 'disable'
> string message both received from ctl-fd descriptor. Completion message is
> 'ack\n' and sent to ack-fd descriptor.
> 
> Example bash script demonstrating simple use case follows:
> 
> #!/bin/bash
> 
> ctl_dir=/tmp/
> 
> ctl_fifo=${ctl_dir}perf_ctl.fifo
> test -p ${ctl_fifo} && unlink ${ctl_fifo}
> mkfifo ${ctl_fifo} && exec {ctl_fd}<>${ctl_fifo}
> 
> ctl_ack_fifo=${ctl_dir}perf_ctl_ack.fifo
> test -p ${ctl_ack_fifo} && unlink ${ctl_ack_fifo}
> mkfifo ${ctl_ack_fifo} && exec {ctl_fd_ack}<>${ctl_ack_fifo}
> 
> perf stat -D -1 -e cpu-cycles -a -I 1000       \
>           --control fd:${ctl_fd},${ctl_fd_ack} \
>           -- sleep 40 &
> perf_pid=$!
> 
> sleep 5  && echo 'enable' >&${ctl_fd} && read -u ${ctl_fd_ack} e1 && echo "enabled(${e1})"
> sleep 10 && echo 'disable' >&${ctl_fd} && read -u ${ctl_fd_ack} d1 && echo "disabled(${d1})"
> sleep 5  && echo 'enable' >&${ctl_fd} && read -u ${ctl_fd_ack} e2 && echo "enabled(${e2})"
> sleep 10 && echo 'disable' >&${ctl_fd} && read -u ${ctl_fd_ack} d2 && echo "disabled(${d2})"
> 
> exec {ctl_fd_ack}>&- && unlink ${ctl_ack_fifo}
> exec {ctl_fd}>&- && unlink ${ctl_fifo}
> 
> wait -n ${perf_pid}
> exit $?
> 
> 
> Script output:
> 
> [root@host dir] example
> Events disabled
> #           time             counts unit events
>      1.001101062      <not counted>      cpu-cycles                                                  
>      2.002994944      <not counted>      cpu-cycles                                                  
>      3.004864340      <not counted>      cpu-cycles                                                  
>      4.006727177      <not counted>      cpu-cycles                                                  
> Events enabled
> enabled(ack)
>      4.993808464          3,124,246      cpu-cycles                                                  
>      5.008597004          3,325,624      cpu-cycles                                                  
>      6.010387483         83,472,992      cpu-cycles                                                  
>      7.012266598         55,877,621      cpu-cycles                                                  
>      8.014175695         97,892,729      cpu-cycles                                                  
>      9.016056093         68,461,242      cpu-cycles                                                  
>     10.017937507         55,449,643      cpu-cycles                                                  
>     11.019830154         68,938,167      cpu-cycles                                                  
>     12.021719952         55,164,101      cpu-cycles                                                  
>     13.023627550         70,535,720      cpu-cycles                                                  
>     14.025580995         53,240,125      cpu-cycles                                                  
> disabled(ack)
>     14.997518260         53,558,068      cpu-cycles                                                  
> Events disabled
>     15.027216416      <not counted>      cpu-cycles                                                  
>     16.029052729      <not counted>      cpu-cycles                                                  
>     17.030904762      <not counted>      cpu-cycles                                                  
>     18.032073424      <not counted>      cpu-cycles                                                  
>     19.033805074      <not counted>      cpu-cycles                                                  
> Events enabled
> enabled(ack)
>     20.001279097          3,021,022      cpu-cycles                                                  
>     20.035044381          6,434,367      cpu-cycles                                                  
>     21.036923813         89,358,251      cpu-cycles                                                  
>     22.038825169         72,516,351      cpu-cycles                                                  
> #           time             counts unit events
>     23.040715596         55,046,157      cpu-cycles                                                  
>     24.042643757         78,128,649      cpu-cycles                                                  
>     25.044558535         61,052,428      cpu-cycles                                                  
>     26.046452785         62,142,806      cpu-cycles                                                  
>     27.048353021         74,477,971      cpu-cycles                                                  
>     28.050241286         61,001,623      cpu-cycles                                                  
>     29.052149961         61,653,502      cpu-cycles                                                  
> disabled(ack)
>     30.004980264         82,729,640      cpu-cycles                                                  
> Events disabled
>     30.053516176      <not counted>      cpu-cycles                                                  
>     31.055348366      <not counted>      cpu-cycles                                                  
>     32.057202097      <not counted>      cpu-cycles                                                  
>     33.059040702      <not counted>      cpu-cycles                                                  
>     34.060843288      <not counted>      cpu-cycles                                                  
>     35.000888624      <not counted>      cpu-cycles                                                  
> [root@host dir]# 
> 
> [1] http://man7.org/linux/man-pages/man1/bash.1.html
> [2] http://man7.org/linux/man-pages/man2/pipe.2.html
> 
> ---
> Alexey Budankov (13):
>   tools/libperf: avoid moving of fds at fdarray__filter() call
>   perf evlist: introduce control file descriptors
>   perf evlist: implement control command handling functions
>   perf stat: factor out body of event handling loop for system wide
>   perf stat: move target check to loop control statement
>   perf stat: factor out body of event handling loop for fork case
>   perf stat: factor out event handling loop into dispatch_events()
>   perf stat: extend -D,--delay option with -1 value
>   perf stat: implement control commands handling
>   perf stat: introduce --control fd:ctl-fd[,ack-fd] options
>   perf record: extend -D,--delay option with -1 value
>   perf record: implement control commands handling
>   perf record: introduce --control fd:ctl-fd[,ack-fd] options
> 
>  tools/lib/api/fd/array.c                 |  11 +-
>  tools/perf/Documentation/perf-record.txt |  44 +++++-
>  tools/perf/Documentation/perf-stat.txt   |  44 +++++-
>  tools/perf/builtin-record.c              |  65 ++++++++-
>  tools/perf/builtin-stat.c                | 176 ++++++++++++++++++-----
>  tools/perf/builtin-trace.c               |   2 +-
>  tools/perf/tests/fdarray.c               |  20 +--
>  tools/perf/util/evlist.c                 | 136 ++++++++++++++++++
>  tools/perf/util/evlist.h                 |  25 ++++
>  tools/perf/util/record.h                 |   4 +-
>  tools/perf/util/stat.h                   |   4 +-
>  11 files changed, 458 insertions(+), 73 deletions(-)
> 

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes
  2020-06-22  3:38 ` [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
@ 2020-06-22  8:55   ` Jiri Olsa
  0 siblings, 0 replies; 49+ messages in thread
From: Jiri Olsa @ 2020-06-22  8:55 UTC (permalink / raw)
  To: Alexey Budankov
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Mon, Jun 22, 2020 at 06:38:34AM +0300, Alexey Budankov wrote:
> 
> Hi,
> 
> On 17.06.2020 11:30, Alexey Budankov wrote:
> > 
> > Changes in v8:
> > - avoided moving of fds at fdarray__filter() call
> > - skipped counting of fds with zeroed revents at fdarray__filter() call
> > - converted explicit --ctl-fd[-ack] into --control fd:ctl-fd[,ack-fd option 
> > - updated docs to accommodate --control fd:ctl-fd[,ack-fd] option
> 
> Are there any questions or thoughts so far?

hi,
I'm waiting on some comment for:
  https://lore.kernel.org/lkml/20200615165802.GD2088119@krava/

jirka

> 
> Thanks,
> Alexey
> 
> > 
> > v7: https://lore.kernel.org/lkml/5de4b954-24f0-1e8d-5a0d-7b12783b8218@linux.intel.com/
> > 
> > Changes in v7:
> > - added missing perf-record.txt changes 
> > - adjusted docs wording for --ctl-fd,ctl-fd-ack options 
> >   to additionally mention --delay=-1 effect
> > 
> > v6: https://lore.kernel.org/lkml/f8e3a714-d9b1-4647-e1d2-9981cbaa83ec@linux.intel.com/
> > 
> > Changes in v6:
> > - split re-factoring of events handling loops for stat mode
> >   into smaller incremental parts
> > - added parts missing at v5
> > - corrected v5 runtime issues
> > 
> > v5: https://lore.kernel.org/lkml/e5cac8dd-7aa4-ec7c-671c-07756907acba@linux.intel.com/
> > 
> > Changes in v5:
> > - split re-factoring of events handling loops for stat mode
> >   into smaller incremental parts
> > 
> > v4: https://lore.kernel.org/lkml/653fe5f3-c986-a841-1ed8-0a7d2fa24c00@linux.intel.com/
> > 
> > Changes in v4:
> > - made checking of ctlfd state unconditional in record trace streaming loop
> > - introduced static poll fds to keep evlist__filter_pollfd() unaffected
> > - handled ret code of evlist__initialize_ctlfd() where need
> > - renamed and structured handle_events() function
> > - applied anonymous structs where needed
> > 
> > v3: https://lore.kernel.org/lkml/eb38e9e5-754f-d410-1d9b-e26b702d51b7@linux.intel.com/
> > 
> > Changes in v3:
> > - renamed functions and types from perf_evlist_ to evlist_ to avoid
> >   clash with libperf code;
> > - extended commands to be strings of variable length consisting of
> >   command name and also possibly including command specific data;
> > - merged docs update with the code changes;
> > - updated docs for -D,--delay=-1 option for stat and record modes;
> > 
> > v2: https://lore.kernel.org/lkml/d582cc3d-2302-c7e2-70d3-bc7ab6f628c3@linux.intel.com/
> > 
> > Changes in v2:
> > - renamed resume and pause commands to enable and disable ones, renamed
> >   CTL_CMD_RESUME and CTL_CMD_PAUSE to CTL_CMD_ENABLE and CTL_CMD_DISABLE
> >   to fit to the appropriate ioctls and avoid mixing up with PAUSE_OUTPUT
> >   ioctl;
> > - factored out event handling loop into a handle_events() for stat mode;
> > - separated -D,--delay=-1 into separate patches for stat and record modes;
> > 
> > v1: https://lore.kernel.org/lkml/825a5132-b58d-c0b6-b050-5a6040386ec7@linux.intel.com/
> > 
> > repo: tip of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git perf/core
> > 
> > The patch set implements handling of 'start disabled', 'enable' and 'disable'
> > external control commands which can be provided for stat and record modes
> > of the tool from an external controlling process. 'start disabled' command
> > can be used to postpone enabling of events in the beginning of a monitoring
> > session. 'enable' and 'disable' commands can be used to enable and disable
> > events correspondingly any time after the start of the session.
> > 
> > The 'start disabled', 'enable' and 'disable' external control commands can be
> > used to focus measurement on specially selected time intervals of workload
> > execution. Focused measurement reduces tool intrusion and influence on
> > workload behavior, reduces distortion and amount of collected and stored
> > data, mitigates data accuracy loss because measurement and data capturing
> > happen only during intervals of interest.
> > 
> > A controlling process can be a bash shell script [1], native executable or
> > any other language program that can directly work with file descriptors,
> > e.g. pipes [2], and spawn a process, specially the tool one.
> > 
> > -D,--delay <val> option is extended with -1 value to skip events enabling
> > in the beginning of a monitoring session ('start disabled' command).
> > --control fd:ctl-fd[,ack-fd] command line option is introduced to provide the
> > tool with a pair of file descriptors to listen to control commands and reply
> > to the controlling process on the completion of received commands.
> > 
> > The tool reads control command message from ctl-fd descriptor, handles the
> > command and optionally replies acknowledgement message to ack-fd descriptor,
> > if it is specified on the command line. 'enable' command is recognized as
> > 'enable' string message and 'disable' command is recognized as 'disable'
> > string message both received from ctl-fd descriptor. Completion message is
> > 'ack\n' and sent to ack-fd descriptor.
> > 
> > Example bash script demonstrating simple use case follows:
> > 
> > #!/bin/bash
> > 
> > ctl_dir=/tmp/
> > 
> > ctl_fifo=${ctl_dir}perf_ctl.fifo
> > test -p ${ctl_fifo} && unlink ${ctl_fifo}
> > mkfifo ${ctl_fifo} && exec {ctl_fd}<>${ctl_fifo}
> > 
> > ctl_ack_fifo=${ctl_dir}perf_ctl_ack.fifo
> > test -p ${ctl_ack_fifo} && unlink ${ctl_ack_fifo}
> > mkfifo ${ctl_ack_fifo} && exec {ctl_fd_ack}<>${ctl_ack_fifo}
> > 
> > perf stat -D -1 -e cpu-cycles -a -I 1000       \
> >           --control fd:${ctl_fd},${ctl_fd_ack} \
> >           -- sleep 40 &
> > perf_pid=$!
> > 
> > sleep 5  && echo 'enable' >&${ctl_fd} && read -u ${ctl_fd_ack} e1 && echo "enabled(${e1})"
> > sleep 10 && echo 'disable' >&${ctl_fd} && read -u ${ctl_fd_ack} d1 && echo "disabled(${d1})"
> > sleep 5  && echo 'enable' >&${ctl_fd} && read -u ${ctl_fd_ack} e2 && echo "enabled(${e2})"
> > sleep 10 && echo 'disable' >&${ctl_fd} && read -u ${ctl_fd_ack} d2 && echo "disabled(${d2})"
> > 
> > exec {ctl_fd_ack}>&- && unlink ${ctl_ack_fifo}
> > exec {ctl_fd}>&- && unlink ${ctl_fifo}
> > 
> > wait -n ${perf_pid}
> > exit $?
> > 
> > 
> > Script output:
> > 
> > [root@host dir] example
> > Events disabled
> > #           time             counts unit events
> >      1.001101062      <not counted>      cpu-cycles                                                  
> >      2.002994944      <not counted>      cpu-cycles                                                  
> >      3.004864340      <not counted>      cpu-cycles                                                  
> >      4.006727177      <not counted>      cpu-cycles                                                  
> > Events enabled
> > enabled(ack)
> >      4.993808464          3,124,246      cpu-cycles                                                  
> >      5.008597004          3,325,624      cpu-cycles                                                  
> >      6.010387483         83,472,992      cpu-cycles                                                  
> >      7.012266598         55,877,621      cpu-cycles                                                  
> >      8.014175695         97,892,729      cpu-cycles                                                  
> >      9.016056093         68,461,242      cpu-cycles                                                  
> >     10.017937507         55,449,643      cpu-cycles                                                  
> >     11.019830154         68,938,167      cpu-cycles                                                  
> >     12.021719952         55,164,101      cpu-cycles                                                  
> >     13.023627550         70,535,720      cpu-cycles                                                  
> >     14.025580995         53,240,125      cpu-cycles                                                  
> > disabled(ack)
> >     14.997518260         53,558,068      cpu-cycles                                                  
> > Events disabled
> >     15.027216416      <not counted>      cpu-cycles                                                  
> >     16.029052729      <not counted>      cpu-cycles                                                  
> >     17.030904762      <not counted>      cpu-cycles                                                  
> >     18.032073424      <not counted>      cpu-cycles                                                  
> >     19.033805074      <not counted>      cpu-cycles                                                  
> > Events enabled
> > enabled(ack)
> >     20.001279097          3,021,022      cpu-cycles                                                  
> >     20.035044381          6,434,367      cpu-cycles                                                  
> >     21.036923813         89,358,251      cpu-cycles                                                  
> >     22.038825169         72,516,351      cpu-cycles                                                  
> > #           time             counts unit events
> >     23.040715596         55,046,157      cpu-cycles                                                  
> >     24.042643757         78,128,649      cpu-cycles                                                  
> >     25.044558535         61,052,428      cpu-cycles                                                  
> >     26.046452785         62,142,806      cpu-cycles                                                  
> >     27.048353021         74,477,971      cpu-cycles                                                  
> >     28.050241286         61,001,623      cpu-cycles                                                  
> >     29.052149961         61,653,502      cpu-cycles                                                  
> > disabled(ack)
> >     30.004980264         82,729,640      cpu-cycles                                                  
> > Events disabled
> >     30.053516176      <not counted>      cpu-cycles                                                  
> >     31.055348366      <not counted>      cpu-cycles                                                  
> >     32.057202097      <not counted>      cpu-cycles                                                  
> >     33.059040702      <not counted>      cpu-cycles                                                  
> >     34.060843288      <not counted>      cpu-cycles                                                  
> >     35.000888624      <not counted>      cpu-cycles                                                  
> > [root@host dir]# 
> > 
> > [1] http://man7.org/linux/man-pages/man1/bash.1.html
> > [2] http://man7.org/linux/man-pages/man2/pipe.2.html
> > 
> > ---
> > Alexey Budankov (13):
> >   tools/libperf: avoid moving of fds at fdarray__filter() call
> >   perf evlist: introduce control file descriptors
> >   perf evlist: implement control command handling functions
> >   perf stat: factor out body of event handling loop for system wide
> >   perf stat: move target check to loop control statement
> >   perf stat: factor out body of event handling loop for fork case
> >   perf stat: factor out event handling loop into dispatch_events()
> >   perf stat: extend -D,--delay option with -1 value
> >   perf stat: implement control commands handling
> >   perf stat: introduce --control fd:ctl-fd[,ack-fd] options
> >   perf record: extend -D,--delay option with -1 value
> >   perf record: implement control commands handling
> >   perf record: introduce --control fd:ctl-fd[,ack-fd] options
> > 
> >  tools/lib/api/fd/array.c                 |  11 +-
> >  tools/perf/Documentation/perf-record.txt |  44 +++++-
> >  tools/perf/Documentation/perf-stat.txt   |  44 +++++-
> >  tools/perf/builtin-record.c              |  65 ++++++++-
> >  tools/perf/builtin-stat.c                | 176 ++++++++++++++++++-----
> >  tools/perf/builtin-trace.c               |   2 +-
> >  tools/perf/tests/fdarray.c               |  20 +--
> >  tools/perf/util/evlist.c                 | 136 ++++++++++++++++++
> >  tools/perf/util/evlist.h                 |  25 ++++
> >  tools/perf/util/record.h                 |   4 +-
> >  tools/perf/util/stat.h                   |   4 +-
> >  11 files changed, 458 insertions(+), 73 deletions(-)
> > 
> 


^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 12/13] perf record: implement control commands handling
  2020-06-17  8:43 ` [PATCH v8 12/13] perf record: implement control commands handling Alexey Budankov
@ 2020-06-23 14:54   ` Jiri Olsa
  2020-06-24 14:00     ` Alexey Budankov
  0 siblings, 1 reply; 49+ messages in thread
From: Jiri Olsa @ 2020-06-23 14:54 UTC (permalink / raw)
  To: Alexey Budankov
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Wed, Jun 17, 2020 at 11:43:58AM +0300, Alexey Budankov wrote:
> 
> Implement handling of 'enable' and 'disable' control commands
> coming from control file descriptor.
> 
> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
> ---
>  tools/perf/builtin-record.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index d0b29a1070a0..0394e068dde8 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -1527,6 +1527,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
>  	bool disabled = false, draining = false;
>  	int fd;
>  	float ratio = 0;
> +	enum evlist_ctl_cmd cmd = EVLIST_CTL_CMD_UNSUPPORTED;
>  
>  	atexit(record__sig_exit);
>  	signal(SIGCHLD, sig_handler);
> @@ -1830,6 +1831,21 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
>  				alarm(rec->switch_output.time);
>  		}
>  
> +		if (evlist__ctlfd_process(rec->evlist, &cmd) > 0) {
> +			switch (cmd) {
> +			case EVLIST_CTL_CMD_ENABLE:
> +				pr_info(EVLIST_ENABLED_MSG);
> +				break;
> +			case EVLIST_CTL_CMD_DISABLE:
> +				pr_info(EVLIST_DISABLED_MSG);
> +				break;
> +			case EVLIST_CTL_CMD_ACK:
> +			case EVLIST_CTL_CMD_UNSUPPORTED:
> +			default:
> +				break;
> +			}
> +		}

so there's still the filter call like:

                        if (evlist__filter_pollfd(rec->evlist, POLLERR | POLLHUP) == 0)
                                draining = true;

it will never be 0 if the control fds are stil alive no?

jirka


^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 09/13] perf stat: implement control commands handling
  2020-06-17  8:41 ` [PATCH v8 09/13] perf stat: implement control commands handling Alexey Budankov
@ 2020-06-23 14:54   ` Jiri Olsa
  2020-06-24 14:10     ` Alexey Budankov
  2020-06-23 14:54   ` Jiri Olsa
  1 sibling, 1 reply; 49+ messages in thread
From: Jiri Olsa @ 2020-06-23 14:54 UTC (permalink / raw)
  To: Alexey Budankov
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Wed, Jun 17, 2020 at 11:41:30AM +0300, Alexey Budankov wrote:

SNIP

>  
>  	while (1) {
>  		if (forks)
> @@ -581,8 +617,17 @@ static int dispatch_events(bool forks, int timeout, int interval, int *times, st
>  		if (done || stop || child)
>  			break;
>  
> -		nanosleep(ts, NULL);
> -		stop = process_timeout(timeout, interval, times);
> +		clock_gettime(CLOCK_MONOTONIC, &time_start);
> +		if (!(evlist__poll(evsel_list, time_to_sleep) > 0)) { /* poll timeout or EINTR */
> +			stop = process_timeout(timeout, interval, times);
> +			time_to_sleep = sleep_time;
> +		} else { /* fd revent */
> +			stop = process_evlist(evsel_list, interval, times);
> +			clock_gettime(CLOCK_MONOTONIC, &time_stop);
> +			diff_timespec(&time_diff, &time_stop, &time_start);
> +			time_to_sleep -= time_diff.tv_sec * MSEC_PER_SEC +
> +					time_diff.tv_nsec / NSEC_PER_MSEC;

should we check time_to_sleep > time_diff first?

jirka


^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 09/13] perf stat: implement control commands handling
  2020-06-17  8:41 ` [PATCH v8 09/13] perf stat: implement control commands handling Alexey Budankov
  2020-06-23 14:54   ` Jiri Olsa
@ 2020-06-23 14:54   ` Jiri Olsa
  2020-06-24 13:39     ` Alexey Budankov
  1 sibling, 1 reply; 49+ messages in thread
From: Jiri Olsa @ 2020-06-23 14:54 UTC (permalink / raw)
  To: Alexey Budankov
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Wed, Jun 17, 2020 at 11:41:30AM +0300, Alexey Budankov wrote:
> 
> Implement handling of 'enable' and 'disable' control commands
> coming from control file descriptor. process_evlist() function
> checks for events on control fds and makes required operations.
> If poll event splits initiated timeout interval then the reminder
> is calculated and still waited in the following poll() syscall.
> 
> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
> ---
>  tools/perf/builtin-stat.c | 67 +++++++++++++++++++++++++++++----------
>  1 file changed, 50 insertions(+), 17 deletions(-)
> 
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index f88d5ee55022..cc56d71a3ed5 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -492,6 +492,31 @@ static bool process_timeout(int timeout, unsigned int interval, int *times)
>  	return print_interval(interval, times);
>  }
>  
> +static bool process_evlist(struct evlist *evlist, unsigned int interval, int *times)
> +{
> +	bool stop = false;
> +	enum evlist_ctl_cmd cmd = EVLIST_CTL_CMD_UNSUPPORTED;
> +
> +	if (evlist__ctlfd_process(evlist, &cmd) > 0) {
> +		switch (cmd) {
> +		case EVLIST_CTL_CMD_ENABLE:
> +			pr_info(EVLIST_ENABLED_MSG);
> +			stop = print_interval(interval, times);

why is interval printed in here?

> +			break;
> +		case EVLIST_CTL_CMD_DISABLE:
> +			stop = print_interval(interval, times);

and here?

it should be called from the main loop when the interval time is elapsed no?

jirka


^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 03/13] perf evlist: implement control command handling functions
  2020-06-17  8:36 ` [PATCH v8 03/13] perf evlist: implement control command handling functions Alexey Budankov
@ 2020-06-23 14:56   ` Jiri Olsa
  2020-06-23 15:03     ` Arnaldo Carvalho de Melo
  2020-06-23 14:56   ` Jiri Olsa
  1 sibling, 1 reply; 49+ messages in thread
From: Jiri Olsa @ 2020-06-23 14:56 UTC (permalink / raw)
  To: Alexey Budankov
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Wed, Jun 17, 2020 at 11:36:46AM +0300, Alexey Budankov wrote:

SNIP

> +	memset(cmd_data, 0, data_size--);
> +
> +	do {
> +		err = read(evlist->ctl_fd.fd, &c, 1);
> +		if (err > 0) {
> +			if (c == '\n' || c == '\0')
> +				break;
> +			cmd_data[bytes_read++] = c;
> +			if (bytes_read == data_size)
> +				break;
> +		} else {
> +			if (err == -1)
> +				pr_err("Failed to read from ctlfd %d: %m\n", evlist->ctl_fd.fd);
> +			break;
> +		}
> +	} while (1);
> +
> +	pr_debug("Message from ctl_fd: \"%s%s\"\n", cmd_data,
> +		 bytes_read == data_size ? "" : c == '\n' ? "\\n" : "\\0");
> +
> +	if (err > 0) {
> +		if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG,
> +			     strlen(EVLIST_CTL_CMD_ENABLE_TAG))) {

you could use sizeof(EVLIST_CTL_CMD_ENABLE_TAG) instead, no function call

> +			*cmd = EVLIST_CTL_CMD_ENABLE;
> +		} else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG,
> +				    strlen(EVLIST_CTL_CMD_DISABLE_TAG))) {

ditto

jirka


^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 03/13] perf evlist: implement control command handling functions
  2020-06-17  8:36 ` [PATCH v8 03/13] perf evlist: implement control command handling functions Alexey Budankov
  2020-06-23 14:56   ` Jiri Olsa
@ 2020-06-23 14:56   ` Jiri Olsa
  2020-06-24 13:20     ` Alexey Budankov
  1 sibling, 1 reply; 49+ messages in thread
From: Jiri Olsa @ 2020-06-23 14:56 UTC (permalink / raw)
  To: Alexey Budankov
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Wed, Jun 17, 2020 at 11:36:46AM +0300, Alexey Budankov wrote:

SNIP

> +static int evlist__ctlfd_recv(struct evlist *evlist, enum evlist_ctl_cmd *cmd,
> +			      char *cmd_data, size_t data_size)
> +{
> +	int err;
> +	char c;
> +	size_t bytes_read = 0;
> +
> +	memset(cmd_data, 0, data_size--);
> +
> +	do {
> +		err = read(evlist->ctl_fd.fd, &c, 1);
> +		if (err > 0) {
> +			if (c == '\n' || c == '\0')
> +				break;
> +			cmd_data[bytes_read++] = c;
> +			if (bytes_read == data_size)
> +				break;
> +		} else {
> +			if (err == -1)
> +				pr_err("Failed to read from ctlfd %d: %m\n", evlist->ctl_fd.fd);
> +			break;
> +		}
> +	} while (1);
> +
> +	pr_debug("Message from ctl_fd: \"%s%s\"\n", cmd_data,
> +		 bytes_read == data_size ? "" : c == '\n' ? "\\n" : "\\0");

do you want to display the message above only if (err > 0) ?

> +
> +	if (err > 0) {
> +		if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG,
> +			     strlen(EVLIST_CTL_CMD_ENABLE_TAG))) {
> +			*cmd = EVLIST_CTL_CMD_ENABLE;
> +		} else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG,
> +				    strlen(EVLIST_CTL_CMD_DISABLE_TAG))) {
> +			*cmd = EVLIST_CTL_CMD_DISABLE;
> +		}
> +	}
> +
> +	return err;
> +}

SNIP

> +	int ctlfd_pos = evlist->ctl_fd.pos;
> +	struct pollfd *entries = evlist->core.pollfd.entries;
> +
> +	if (ctlfd_pos == -1 || !entries[ctlfd_pos].revents)
> +		return 0;
> +
> +	if (entries[ctlfd_pos].revents & POLLIN) {
> +		err = evlist__ctlfd_recv(evlist, cmd, cmd_data,
> +					 EVLIST_CTL_CMD_MAX_LEN);
> +		if (err > 0) {
> +			switch (*cmd) {
> +			case EVLIST_CTL_CMD_ENABLE:
> +				evlist__enable(evlist);
> +				break;
> +			case EVLIST_CTL_CMD_DISABLE:
> +				evlist__disable(evlist);
> +				break;
> +			case EVLIST_CTL_CMD_ACK:
> +			case EVLIST_CTL_CMD_UNSUPPORTED:
> +			default:
> +				pr_debug("ctlfd: unsupported %d\n", *cmd);
> +				break;
> +			}
> +			if (!(*cmd == EVLIST_CTL_CMD_ACK || *cmd == EVLIST_CTL_CMD_UNSUPPORTED))
> +				evlist__ctlfd_ack(evlist);
> +		}
> +	}
> +
> +	if (entries[ctlfd_pos].revents & (POLLHUP | POLLERR))
> +		evlist__finalize_ctlfd(evlist);

should this error be propagated via err?

jirka


^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 07/13] perf stat: factor out event handling loop into dispatch_events()
  2020-06-17  8:40 ` [PATCH v8 07/13] perf stat: factor out event handling loop into dispatch_events() Alexey Budankov
@ 2020-06-23 14:56   ` Jiri Olsa
  2020-06-24 13:27     ` Alexey Budankov
  0 siblings, 1 reply; 49+ messages in thread
From: Jiri Olsa @ 2020-06-23 14:56 UTC (permalink / raw)
  To: Alexey Budankov
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Wed, Jun 17, 2020 at 11:40:03AM +0300, Alexey Budankov wrote:
> 
> Consolidate event dispatching loops for fork, attach and system
> wide monitoring use cases into common dispatch_events() function.
> 
> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
> ---
>  tools/perf/builtin-stat.c | 35 ++++++++++++++++++++++++-----------
>  1 file changed, 24 insertions(+), 11 deletions(-)
> 
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index 3bc538576607..39749c290508 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -557,6 +557,27 @@ static bool is_target_alive(struct target *_target,
>  	return false;
>  }
>  
> +static int dispatch_events(bool forks, int timeout, int interval, int *times, struct timespec *ts)
> +{
> +	bool stop = false;
> +	int child = 0, status = 0;
> +
> +	while (1) {
> +		if (forks)
> +			child = waitpid(child_pid, &status, WNOHANG);
> +		else
> +			child = !is_target_alive(&target, evsel_list->core.threads) ? 1 : 0;

please renme child to something more accurate, so the condition
below makes more sense, like child_stoped or such

jirka

> +
> +		if (done || stop || child)
> +			break;
> +
> +		nanosleep(ts, NULL);
> +		stop = process_timeout(timeout, interval, times);
> +	}
> +
> +	return status;
> +}
> +

SNIP


^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 04/13] perf stat: factor out body of event handling loop for system wide
  2020-06-17  8:37 ` [PATCH v8 04/13] perf stat: factor out body of event handling loop for system wide Alexey Budankov
@ 2020-06-23 14:56   ` Jiri Olsa
  2020-06-24 14:27     ` Alexey Budankov
  0 siblings, 1 reply; 49+ messages in thread
From: Jiri Olsa @ 2020-06-23 14:56 UTC (permalink / raw)
  To: Alexey Budankov
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Wed, Jun 17, 2020 at 11:37:43AM +0300, Alexey Budankov wrote:
> 
> Introduce process_timeout() and process_interval() functions that
> factor out body of event handling loop for attach and system wide
> monitoring use cases.
> 
> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
> ---
>  tools/perf/builtin-stat.c | 28 ++++++++++++++++++++--------
>  1 file changed, 20 insertions(+), 8 deletions(-)
> 
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index 9be020e0098a..31f7ccf9537b 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -475,6 +475,23 @@ static void process_interval(void)
>  	print_counters(&rs, 0, NULL);
>  }
>  
> +static bool print_interval(unsigned int interval, int *times)
> +{
> +	if (interval) {
> +		process_interval();
> +		if (interval_count && !(--(*times)))
> +			return true;
> +	}
> +	return false;
> +}
> +
> +static bool process_timeout(int timeout, unsigned int interval, int *times)
> +{
> +	if (timeout)
> +		return true;
> +	return print_interval(interval, times);
> +}

I think it's confusing to keep this together, that
process_timeout triggers also interval processing

I think you can keep the timeout separated from interval
processing and rename the print_interval to process_interval
and process_interval to __process_interval

jirka

> +
>  static void enable_counters(void)
>  {
>  	if (stat_config.initial_delay)
> @@ -611,6 +628,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
>  	struct affinity affinity;
>  	int i, cpu;
>  	bool second_pass = false;
> +	bool stop = false;
>  
>  	if (interval) {
>  		ts.tv_sec  = interval / USEC_PER_MSEC;
> @@ -805,17 +823,11 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
>  			psignal(WTERMSIG(status), argv[0]);
>  	} else {
>  		enable_counters();
> -		while (!done) {
> +		while (!done && !stop) {
>  			nanosleep(&ts, NULL);
>  			if (!is_target_alive(&target, evsel_list->core.threads))
>  				break;
> -			if (timeout)
> -				break;
> -			if (interval) {
> -				process_interval();
> -				if (interval_count && !(--times))
> -					break;
> -			}
> +			stop = process_timeout(timeout, interval, &times);
>  		}
>  	}
>  
> -- 
> 2.24.1
> 
> 


^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 03/13] perf evlist: implement control command handling functions
  2020-06-23 14:56   ` Jiri Olsa
@ 2020-06-23 15:03     ` Arnaldo Carvalho de Melo
  2020-06-23 15:14       ` Jiri Olsa
  0 siblings, 1 reply; 49+ messages in thread
From: Arnaldo Carvalho de Melo @ 2020-06-23 15:03 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Alexey Budankov, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

Em Tue, Jun 23, 2020 at 04:56:01PM +0200, Jiri Olsa escreveu:
> On Wed, Jun 17, 2020 at 11:36:46AM +0300, Alexey Budankov wrote:
> 
> SNIP
> 
> > +	memset(cmd_data, 0, data_size--);
> > +
> > +	do {
> > +		err = read(evlist->ctl_fd.fd, &c, 1);
> > +		if (err > 0) {
> > +			if (c == '\n' || c == '\0')
> > +				break;
> > +			cmd_data[bytes_read++] = c;
> > +			if (bytes_read == data_size)
> > +				break;
> > +		} else {
> > +			if (err == -1)
> > +				pr_err("Failed to read from ctlfd %d: %m\n", evlist->ctl_fd.fd);
> > +			break;
> > +		}
> > +	} while (1);
> > +
> > +	pr_debug("Message from ctl_fd: \"%s%s\"\n", cmd_data,
> > +		 bytes_read == data_size ? "" : c == '\n' ? "\\n" : "\\0");
> > +
> > +	if (err > 0) {
> > +		if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG,
> > +			     strlen(EVLIST_CTL_CMD_ENABLE_TAG))) {
> 
> you could use sizeof(EVLIST_CTL_CMD_ENABLE_TAG) instead, no function call

-1, as sizeof will get the \0, right?

> 
> > +			*cmd = EVLIST_CTL_CMD_ENABLE;
> > +		} else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG,
> > +				    strlen(EVLIST_CTL_CMD_DISABLE_TAG))) {
> 
> ditto
> 
> jirka
> 

-- 

- Arnaldo

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 03/13] perf evlist: implement control command handling functions
  2020-06-23 15:03     ` Arnaldo Carvalho de Melo
@ 2020-06-23 15:14       ` Jiri Olsa
  2020-06-24 13:35         ` Alexey Budankov
  0 siblings, 1 reply; 49+ messages in thread
From: Jiri Olsa @ 2020-06-23 15:14 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Alexey Budankov, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Tue, Jun 23, 2020 at 12:03:45PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Tue, Jun 23, 2020 at 04:56:01PM +0200, Jiri Olsa escreveu:
> > On Wed, Jun 17, 2020 at 11:36:46AM +0300, Alexey Budankov wrote:
> > 
> > SNIP
> > 
> > > +	memset(cmd_data, 0, data_size--);
> > > +
> > > +	do {
> > > +		err = read(evlist->ctl_fd.fd, &c, 1);
> > > +		if (err > 0) {
> > > +			if (c == '\n' || c == '\0')
> > > +				break;
> > > +			cmd_data[bytes_read++] = c;
> > > +			if (bytes_read == data_size)
> > > +				break;
> > > +		} else {
> > > +			if (err == -1)
> > > +				pr_err("Failed to read from ctlfd %d: %m\n", evlist->ctl_fd.fd);
> > > +			break;
> > > +		}
> > > +	} while (1);
> > > +
> > > +	pr_debug("Message from ctl_fd: \"%s%s\"\n", cmd_data,
> > > +		 bytes_read == data_size ? "" : c == '\n' ? "\\n" : "\\0");
> > > +
> > > +	if (err > 0) {
> > > +		if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG,
> > > +			     strlen(EVLIST_CTL_CMD_ENABLE_TAG))) {
> > 
> > you could use sizeof(EVLIST_CTL_CMD_ENABLE_TAG) instead, no function call
> 
> -1, as sizeof will get the \0, right?

yep, I think that's right

jirka

> 
> > 
> > > +			*cmd = EVLIST_CTL_CMD_ENABLE;
> > > +		} else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG,
> > > +				    strlen(EVLIST_CTL_CMD_DISABLE_TAG))) {
> > 
> > ditto
> > 
> > jirka
> > 
> 
> -- 
> 
> - Arnaldo
> 


^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 03/13] perf evlist: implement control command handling functions
  2020-06-23 14:56   ` Jiri Olsa
@ 2020-06-24 13:20     ` Alexey Budankov
  0 siblings, 0 replies; 49+ messages in thread
From: Alexey Budankov @ 2020-06-24 13:20 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel


On 23.06.2020 17:56, Jiri Olsa wrote:
> On Wed, Jun 17, 2020 at 11:36:46AM +0300, Alexey Budankov wrote:
> 
> SNIP
> 
>> +static int evlist__ctlfd_recv(struct evlist *evlist, enum evlist_ctl_cmd *cmd,
>> +			      char *cmd_data, size_t data_size)
>> +{
>> +	int err;
>> +	char c;
>> +	size_t bytes_read = 0;
>> +
>> +	memset(cmd_data, 0, data_size--);
>> +
>> +	do {
>> +		err = read(evlist->ctl_fd.fd, &c, 1);
>> +		if (err > 0) {
>> +			if (c == '\n' || c == '\0')
>> +				break;
>> +			cmd_data[bytes_read++] = c;
>> +			if (bytes_read == data_size)
>> +				break;
>> +		} else {
>> +			if (err == -1)
>> +				pr_err("Failed to read from ctlfd %d: %m\n", evlist->ctl_fd.fd);
>> +			break;
>> +		}
>> +	} while (1);
>> +
>> +	pr_debug("Message from ctl_fd: \"%s%s\"\n", cmd_data,
>> +		 bytes_read == data_size ? "" : c == '\n' ? "\\n" : "\\0");
> 
> do you want to display the message above only if (err > 0) ?

I do, only for err >= 0. For err == -1 there is already the error message.

> 
>> +
>> +	if (err > 0) {
>> +		if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG,
>> +			     strlen(EVLIST_CTL_CMD_ENABLE_TAG))) {
>> +			*cmd = EVLIST_CTL_CMD_ENABLE;
>> +		} else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG,
>> +				    strlen(EVLIST_CTL_CMD_DISABLE_TAG))) {
>> +			*cmd = EVLIST_CTL_CMD_DISABLE;
>> +		}
>> +	}
>> +
>> +	return err;
>> +}
> 
> SNIP
> 
>> +	int ctlfd_pos = evlist->ctl_fd.pos;
>> +	struct pollfd *entries = evlist->core.pollfd.entries;
>> +
>> +	if (ctlfd_pos == -1 || !entries[ctlfd_pos].revents)
>> +		return 0;
>> +
>> +	if (entries[ctlfd_pos].revents & POLLIN) {
>> +		err = evlist__ctlfd_recv(evlist, cmd, cmd_data,
>> +					 EVLIST_CTL_CMD_MAX_LEN);
>> +		if (err > 0) {
>> +			switch (*cmd) {
>> +			case EVLIST_CTL_CMD_ENABLE:
>> +				evlist__enable(evlist);
>> +				break;
>> +			case EVLIST_CTL_CMD_DISABLE:
>> +				evlist__disable(evlist);
>> +				break;
>> +			case EVLIST_CTL_CMD_ACK:
>> +			case EVLIST_CTL_CMD_UNSUPPORTED:
>> +			default:
>> +				pr_debug("ctlfd: unsupported %d\n", *cmd);
>> +				break;
>> +			}
>> +			if (!(*cmd == EVLIST_CTL_CMD_ACK || *cmd == EVLIST_CTL_CMD_UNSUPPORTED))
>> +				evlist__ctlfd_ack(evlist);
>> +		}
>> +	}
>> +
>> +	if (entries[ctlfd_pos].revents & (POLLHUP | POLLERR))
>> +		evlist__finalize_ctlfd(evlist);
> 
> should this error be propagated via err?

I don't think so. Currently it returns 0 only and there is no need to 
stop collection or skip processing in caller in this case.

~Alexey

> 
> jirka
> 

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 07/13] perf stat: factor out event handling loop into dispatch_events()
  2020-06-23 14:56   ` Jiri Olsa
@ 2020-06-24 13:27     ` Alexey Budankov
  0 siblings, 0 replies; 49+ messages in thread
From: Alexey Budankov @ 2020-06-24 13:27 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel


On 23.06.2020 17:56, Jiri Olsa wrote:
> On Wed, Jun 17, 2020 at 11:40:03AM +0300, Alexey Budankov wrote:
>>
>> Consolidate event dispatching loops for fork, attach and system
>> wide monitoring use cases into common dispatch_events() function.
>>
>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
>> ---
>>  tools/perf/builtin-stat.c | 35 ++++++++++++++++++++++++-----------
>>  1 file changed, 24 insertions(+), 11 deletions(-)
>>
>> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
>> index 3bc538576607..39749c290508 100644
>> --- a/tools/perf/builtin-stat.c
>> +++ b/tools/perf/builtin-stat.c
>> @@ -557,6 +557,27 @@ static bool is_target_alive(struct target *_target,
>>  	return false;
>>  }
>>  
>> +static int dispatch_events(bool forks, int timeout, int interval, int *times, struct timespec *ts)
>> +{
>> +	bool stop = false;
>> +	int child = 0, status = 0;
>> +
>> +	while (1) {
>> +		if (forks)
>> +			child = waitpid(child_pid, &status, WNOHANG);
>> +		else
>> +			child = !is_target_alive(&target, evsel_list->core.threads) ? 1 : 0;
> 
> please renme child to something more accurate, so the condition
> below makes more sense, like child_stoped or such

Well, let's have it named like  child_stopped.

~Alexey

> 
> jirka
> 
>> +
>> +		if (done || stop || child)
>> +			break;
>> +
>> +		nanosleep(ts, NULL);
>> +		stop = process_timeout(timeout, interval, times);
>> +	}
>> +
>> +	return status;
>> +}
>> +
> 
> SNIP
> 

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 03/13] perf evlist: implement control command handling functions
  2020-06-23 15:14       ` Jiri Olsa
@ 2020-06-24 13:35         ` Alexey Budankov
  0 siblings, 0 replies; 49+ messages in thread
From: Alexey Budankov @ 2020-06-24 13:35 UTC (permalink / raw)
  To: Jiri Olsa, Arnaldo Carvalho de Melo
  Cc: Namhyung Kim, Alexander Shishkin, Peter Zijlstra, Ingo Molnar,
	Andi Kleen, linux-kernel



On 23.06.2020 18:14, Jiri Olsa wrote:
> On Tue, Jun 23, 2020 at 12:03:45PM -0300, Arnaldo Carvalho de Melo wrote:
>> Em Tue, Jun 23, 2020 at 04:56:01PM +0200, Jiri Olsa escreveu:
>>> On Wed, Jun 17, 2020 at 11:36:46AM +0300, Alexey Budankov wrote:
>>>
>>> SNIP
>>>
>>>> +	memset(cmd_data, 0, data_size--);
>>>> +
>>>> +	do {
>>>> +		err = read(evlist->ctl_fd.fd, &c, 1);
>>>> +		if (err > 0) {
>>>> +			if (c == '\n' || c == '\0')
>>>> +				break;
>>>> +			cmd_data[bytes_read++] = c;
>>>> +			if (bytes_read == data_size)
>>>> +				break;
>>>> +		} else {
>>>> +			if (err == -1)
>>>> +				pr_err("Failed to read from ctlfd %d: %m\n", evlist->ctl_fd.fd);
>>>> +			break;
>>>> +		}
>>>> +	} while (1);
>>>> +
>>>> +	pr_debug("Message from ctl_fd: \"%s%s\"\n", cmd_data,
>>>> +		 bytes_read == data_size ? "" : c == '\n' ? "\\n" : "\\0");
>>>> +
>>>> +	if (err > 0) {
>>>> +		if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG,
>>>> +			     strlen(EVLIST_CTL_CMD_ENABLE_TAG))) {
>>>
>>> you could use sizeof(EVLIST_CTL_CMD_ENABLE_TAG) instead, no function call
>>
>> -1, as sizeof will get the \0, right?
> 
> yep, I think that's right

Ok, let's have it like (sizeof(EVLIST_CTL_CMD_ENABLE_TAG)-1).

~Alexey

> 
> jirka
> 
>>
>>>
>>>> +			*cmd = EVLIST_CTL_CMD_ENABLE;
>>>> +		} else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG,
>>>> +				    strlen(EVLIST_CTL_CMD_DISABLE_TAG))) {
>>>
>>> ditto
>>>
>>> jirka
>>>
>>
>> -- 
>>
>> - Arnaldo
>>
> 

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 09/13] perf stat: implement control commands handling
  2020-06-23 14:54   ` Jiri Olsa
@ 2020-06-24 13:39     ` Alexey Budankov
  2020-06-25 12:12       ` Jiri Olsa
  0 siblings, 1 reply; 49+ messages in thread
From: Alexey Budankov @ 2020-06-24 13:39 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel



On 23.06.2020 17:54, Jiri Olsa wrote:
> On Wed, Jun 17, 2020 at 11:41:30AM +0300, Alexey Budankov wrote:
>>
>> Implement handling of 'enable' and 'disable' control commands
>> coming from control file descriptor. process_evlist() function
>> checks for events on control fds and makes required operations.
>> If poll event splits initiated timeout interval then the reminder
>> is calculated and still waited in the following poll() syscall.
>>
>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
>> ---
>>  tools/perf/builtin-stat.c | 67 +++++++++++++++++++++++++++++----------
>>  1 file changed, 50 insertions(+), 17 deletions(-)
>>
>> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
>> index f88d5ee55022..cc56d71a3ed5 100644
>> --- a/tools/perf/builtin-stat.c
>> +++ b/tools/perf/builtin-stat.c
>> @@ -492,6 +492,31 @@ static bool process_timeout(int timeout, unsigned int interval, int *times)
>>  	return print_interval(interval, times);
>>  }
>>  
>> +static bool process_evlist(struct evlist *evlist, unsigned int interval, int *times)
>> +{
>> +	bool stop = false;
>> +	enum evlist_ctl_cmd cmd = EVLIST_CTL_CMD_UNSUPPORTED;
>> +
>> +	if (evlist__ctlfd_process(evlist, &cmd) > 0) {
>> +		switch (cmd) {
>> +		case EVLIST_CTL_CMD_ENABLE:
>> +			pr_info(EVLIST_ENABLED_MSG);
>> +			stop = print_interval(interval, times);
> 
> why is interval printed in here?
> 
>> +			break;
>> +		case EVLIST_CTL_CMD_DISABLE:
>> +			stop = print_interval(interval, times);
> 
> and here?
> 
> it should be called from the main loop when the interval time is elapsed no?

It is called from the main loop too and it is also additionally called here
to provide indication and counter values on commands processing times.

~Alexey

> 
> jirka
> 

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 12/13] perf record: implement control commands handling
  2020-06-23 14:54   ` Jiri Olsa
@ 2020-06-24 14:00     ` Alexey Budankov
  2020-06-24 14:55       ` Alexey Budankov
  0 siblings, 1 reply; 49+ messages in thread
From: Alexey Budankov @ 2020-06-24 14:00 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel


On 23.06.2020 17:54, Jiri Olsa wrote:
> On Wed, Jun 17, 2020 at 11:43:58AM +0300, Alexey Budankov wrote:
>>
>> Implement handling of 'enable' and 'disable' control commands
>> coming from control file descriptor.
>>
>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
>> ---
>>  tools/perf/builtin-record.c | 16 ++++++++++++++++
>>  1 file changed, 16 insertions(+)
>>
>> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
>> index d0b29a1070a0..0394e068dde8 100644
>> --- a/tools/perf/builtin-record.c
>> +++ b/tools/perf/builtin-record.c
>> @@ -1527,6 +1527,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
>>  	bool disabled = false, draining = false;
>>  	int fd;
>>  	float ratio = 0;
>> +	enum evlist_ctl_cmd cmd = EVLIST_CTL_CMD_UNSUPPORTED;
>>  
>>  	atexit(record__sig_exit);
>>  	signal(SIGCHLD, sig_handler);
>> @@ -1830,6 +1831,21 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
>>  				alarm(rec->switch_output.time);
>>  		}
>>  
>> +		if (evlist__ctlfd_process(rec->evlist, &cmd) > 0) {
>> +			switch (cmd) {
>> +			case EVLIST_CTL_CMD_ENABLE:
>> +				pr_info(EVLIST_ENABLED_MSG);
>> +				break;
>> +			case EVLIST_CTL_CMD_DISABLE:
>> +				pr_info(EVLIST_DISABLED_MSG);
>> +				break;
>> +			case EVLIST_CTL_CMD_ACK:
>> +			case EVLIST_CTL_CMD_UNSUPPORTED:
>> +			default:
>> +				break;
>> +			}
>> +		}
> 
> so there's still the filter call like:
> 
>                         if (evlist__filter_pollfd(rec->evlist, POLLERR | POLLHUP) == 0)
>                                 draining = true;
> 
> it will never be 0 if the control fds are stil alive no?

Due to change in filter_pollfd() and preceding evlist__ctlfd_process() call
now control fd is not counted by filter_pollfd().

However event fds with .revents == 0 are not counted either and this breaks
the algorithm thus something more is still required to cover this gap.

~Alexey

> 
> jirka
> 

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 09/13] perf stat: implement control commands handling
  2020-06-23 14:54   ` Jiri Olsa
@ 2020-06-24 14:10     ` Alexey Budankov
  2020-06-25 12:14       ` Jiri Olsa
  0 siblings, 1 reply; 49+ messages in thread
From: Alexey Budankov @ 2020-06-24 14:10 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel


On 23.06.2020 17:54, Jiri Olsa wrote:
> On Wed, Jun 17, 2020 at 11:41:30AM +0300, Alexey Budankov wrote:
> 
> SNIP
> 
>>  
>>  	while (1) {
>>  		if (forks)
>> @@ -581,8 +617,17 @@ static int dispatch_events(bool forks, int timeout, int interval, int *times, st
>>  		if (done || stop || child)
>>  			break;
>>  
>> -		nanosleep(ts, NULL);
>> -		stop = process_timeout(timeout, interval, times);
>> +		clock_gettime(CLOCK_MONOTONIC, &time_start);
>> +		if (!(evlist__poll(evsel_list, time_to_sleep) > 0)) { /* poll timeout or EINTR */
>> +			stop = process_timeout(timeout, interval, times);
>> +			time_to_sleep = sleep_time;
>> +		} else { /* fd revent */
>> +			stop = process_evlist(evsel_list, interval, times);
>> +			clock_gettime(CLOCK_MONOTONIC, &time_stop);
>> +			diff_timespec(&time_diff, &time_stop, &time_start);
>> +			time_to_sleep -= time_diff.tv_sec * MSEC_PER_SEC +
>> +					time_diff.tv_nsec / NSEC_PER_MSEC;
> 
> should we check time_to_sleep > time_diff first?

Probably and if time_diff > time_to_sleep then time_to_sleep = 0 ?

~Alexey

> 
> jirka
> 

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 04/13] perf stat: factor out body of event handling loop for system wide
  2020-06-23 14:56   ` Jiri Olsa
@ 2020-06-24 14:27     ` Alexey Budankov
  2020-06-25 12:17       ` Jiri Olsa
  0 siblings, 1 reply; 49+ messages in thread
From: Alexey Budankov @ 2020-06-24 14:27 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel


On 23.06.2020 17:56, Jiri Olsa wrote:
> On Wed, Jun 17, 2020 at 11:37:43AM +0300, Alexey Budankov wrote:
>>
>> Introduce process_timeout() and process_interval() functions that
>> factor out body of event handling loop for attach and system wide
>> monitoring use cases.
>>
>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
>> ---
>>  tools/perf/builtin-stat.c | 28 ++++++++++++++++++++--------
>>  1 file changed, 20 insertions(+), 8 deletions(-)
>>
>> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
>> index 9be020e0098a..31f7ccf9537b 100644
>> --- a/tools/perf/builtin-stat.c
>> +++ b/tools/perf/builtin-stat.c
>> @@ -475,6 +475,23 @@ static void process_interval(void)
>>  	print_counters(&rs, 0, NULL);
>>  }
>>  
>> +static bool print_interval(unsigned int interval, int *times)
>> +{
>> +	if (interval) {
>> +		process_interval();
>> +		if (interval_count && !(--(*times)))
>> +			return true;
>> +	}
>> +	return false;
>> +}
>> +
>> +static bool process_timeout(int timeout, unsigned int interval, int *times)
>> +{
>> +	if (timeout)
>> +		return true;
>> +	return print_interval(interval, times);
>> +}
> 
> I think it's confusing to keep this together, that
> process_timeout triggers also interval processing
> 
> I think you can keep the timeout separated from interval
> processing and rename the print_interval to process_interval
> and process_interval to __process_interval

Well, ok.

I will rename process_interval() to __process_interval() and
then print_interval() to process_interval().

Regarding timeout let's have it like this:

static bool process_timeout(int timeout)
{
	return timeout ? true : false;
}

static bool process_timing_settings(int timeout, unsigned int interval, int *times)
{
        bool res = process_timeout(timeout);
        if (!res)
		res = process_interval(interval, times);
	return res; 
}

Ok?

~Alexey

> 
> jirka
> 
>> +
>>  static void enable_counters(void)
>>  {
>>  	if (stat_config.initial_delay)
>> @@ -611,6 +628,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
>>  	struct affinity affinity;
>>  	int i, cpu;
>>  	bool second_pass = false;
>> +	bool stop = false;
>>  
>>  	if (interval) {
>>  		ts.tv_sec  = interval / USEC_PER_MSEC;
>> @@ -805,17 +823,11 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
>>  			psignal(WTERMSIG(status), argv[0]);
>>  	} else {
>>  		enable_counters();
>> -		while (!done) {
>> +		while (!done && !stop) {
>>  			nanosleep(&ts, NULL);
>>  			if (!is_target_alive(&target, evsel_list->core.threads))
>>  				break;
>> -			if (timeout)
>> -				break;
>> -			if (interval) {
>> -				process_interval();
>> -				if (interval_count && !(--times))
>> -					break;
>> -			}
>> +			stop = process_timeout(timeout, interval, &times);
>>  		}
>>  	}
>>  
>> -- 
>> 2.24.1
>>
>>
> 

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 12/13] perf record: implement control commands handling
  2020-06-24 14:00     ` Alexey Budankov
@ 2020-06-24 14:55       ` Alexey Budankov
  2020-06-25 17:07         ` Jiri Olsa
  0 siblings, 1 reply; 49+ messages in thread
From: Alexey Budankov @ 2020-06-24 14:55 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel


On 24.06.2020 17:00, Alexey Budankov wrote:
> 
> On 23.06.2020 17:54, Jiri Olsa wrote:
>> On Wed, Jun 17, 2020 at 11:43:58AM +0300, Alexey Budankov wrote:
>>>
>>> Implement handling of 'enable' and 'disable' control commands
>>> coming from control file descriptor.
>>>
>>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
>>> ---
>>>  tools/perf/builtin-record.c | 16 ++++++++++++++++
>>>  1 file changed, 16 insertions(+)
>>>
>>> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
>>> index d0b29a1070a0..0394e068dde8 100644
>>> --- a/tools/perf/builtin-record.c
>>> +++ b/tools/perf/builtin-record.c
>>> @@ -1527,6 +1527,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
>>>  	bool disabled = false, draining = false;
>>>  	int fd;
>>>  	float ratio = 0;
>>> +	enum evlist_ctl_cmd cmd = EVLIST_CTL_CMD_UNSUPPORTED;
>>>  
>>>  	atexit(record__sig_exit);
>>>  	signal(SIGCHLD, sig_handler);
>>> @@ -1830,6 +1831,21 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
>>>  				alarm(rec->switch_output.time);
>>>  		}
>>>  
>>> +		if (evlist__ctlfd_process(rec->evlist, &cmd) > 0) {
>>> +			switch (cmd) {
>>> +			case EVLIST_CTL_CMD_ENABLE:
>>> +				pr_info(EVLIST_ENABLED_MSG);
>>> +				break;
>>> +			case EVLIST_CTL_CMD_DISABLE:
>>> +				pr_info(EVLIST_DISABLED_MSG);
>>> +				break;
>>> +			case EVLIST_CTL_CMD_ACK:
>>> +			case EVLIST_CTL_CMD_UNSUPPORTED:
>>> +			default:
>>> +				break;
>>> +			}
>>> +		}
>>
>> so there's still the filter call like:
>>
>>                         if (evlist__filter_pollfd(rec->evlist, POLLERR | POLLHUP) == 0)
>>                                 draining = true;
>>
>> it will never be 0 if the control fds are stil alive no?
> 
> Due to change in filter_pollfd() and preceding evlist__ctlfd_process() call
> now control fd is not counted by filter_pollfd().
And evlist__ctlfd_process() still should be called second time right
after evlist_poll() but prior filter_polfd().

~Alexey

> 
> However event fds with .revents == 0 are not counted either and this breaks
> the algorithm thus something more is still required to cover this gap.
> 
> ~Alexey
> 
>>
>> jirka
>>

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 01/13] tools/libperf: avoid moving of fds at fdarray__filter() call
  2020-06-17  8:35 ` [PATCH v8 01/13] tools/libperf: avoid moving of fds at fdarray__filter() call Alexey Budankov
@ 2020-06-24 17:19   ` Alexey Budankov
  2020-06-25 17:14     ` Jiri Olsa
  0 siblings, 1 reply; 49+ messages in thread
From: Alexey Budankov @ 2020-06-24 17:19 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo, Jiri Olsa
  Cc: Namhyung Kim, Alexander Shishkin, Peter Zijlstra, Ingo Molnar,
	Andi Kleen, linux-kernel


On 17.06.2020 11:35, Alexey Budankov wrote:
> 
> Skip fds with zeroed revents field from count and avoid fds moving
> at fdarray__filter() call so fds indices returned by fdarray__add()
> call stay the same and can be used for direct access and processing
> of fd revents status field at entries array of struct fdarray object.
> 
> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
> ---
>  tools/lib/api/fd/array.c   | 11 +++++------
>  tools/perf/tests/fdarray.c | 20 ++------------------
>  2 files changed, 7 insertions(+), 24 deletions(-)
> 
> diff --git a/tools/lib/api/fd/array.c b/tools/lib/api/fd/array.c
> index 58d44d5eee31..97843a837370 100644
> --- a/tools/lib/api/fd/array.c
> +++ b/tools/lib/api/fd/array.c
> @@ -93,22 +93,21 @@ int fdarray__filter(struct fdarray *fda, short revents,
>  		return 0;
>  
>  	for (fd = 0; fd < fda->nr; ++fd) {
> +		if (!fda->entries[fd].revents)
> +			continue;
> +

So it looks like this condition also filters out non signaling events fds, not only
control and others fds, and this should be somehow avoided so such event related fds
would be counted. Several options have been proposed so far:

1) Explicit typing of fds via API extension and filtering based on the types:
   a) with separate fdarray__add_stat() call
   b) with type arg of existing fdarray__add() call
   c) various memory management design is possible

2) Playing tricks with fd positions inside entries and assumptions on fdarray API calls ordering
   - looks more like a hack than a designed solution

3) Rewrite of fdarray class to allocate separate object for every added fds
   - can be replaced with nonscrewing of fds by __filter()

4) Distinct between fds types at fdarray__filter() using .revents == 0 condition
   - seems to have corner cases and thus not applicable

5) Extension of fdarray__poll(, *arg_ptr, arg_size) with arg of fds array to atomically poll
   on fdarray_add()-ed fds and external arg fds and then external arg fds processing

6) Rewrite of fdarray class on epoll() call basis
   - introduces new scalability restrictions for Perf tool

7) Anything else ...

~Alexey

>  		if (fda->entries[fd].revents & revents) {
>  			if (entry_destructor)
>  				entry_destructor(fda, fd, arg);
>  
> +			fda->entries[fd].revents = fda->entries[fd].events = 0;
>  			continue;
>  		}
>  
> -		if (fd != nr) {
> -			fda->entries[nr] = fda->entries[fd];
> -			fda->priv[nr]	 = fda->priv[fd];
> -		}
> -
>  		++nr;
>  	}
>  
> -	return fda->nr = nr;
> +	return nr;
>  }
>  
>  int fdarray__poll(struct fdarray *fda, int timeout)
> diff --git a/tools/perf/tests/fdarray.c b/tools/perf/tests/fdarray.c
> index c7c81c4a5b2b..d0c8a05aab2f 100644
> --- a/tools/perf/tests/fdarray.c
> +++ b/tools/perf/tests/fdarray.c
> @@ -12,6 +12,7 @@ static void fdarray__init_revents(struct fdarray *fda, short revents)
>  
>  	for (fd = 0; fd < fda->nr; ++fd) {
>  		fda->entries[fd].fd	 = fda->nr - fd;
> +		fda->entries[fd].events  = revents;
>  		fda->entries[fd].revents = revents;
>  	}
>  }
> @@ -29,7 +30,7 @@ static int fdarray__fprintf_prefix(struct fdarray *fda, const char *prefix, FILE
>  
>  int test__fdarray__filter(struct test *test __maybe_unused, int subtest __maybe_unused)
>  {
> -	int nr_fds, expected_fd[2], fd, err = TEST_FAIL;
> +	int nr_fds, err = TEST_FAIL;
>  	struct fdarray *fda = fdarray__new(5, 5);
>  
>  	if (fda == NULL) {
> @@ -55,7 +56,6 @@ int test__fdarray__filter(struct test *test __maybe_unused, int subtest __maybe_
>  
>  	fdarray__init_revents(fda, POLLHUP);
>  	fda->entries[2].revents = POLLIN;
> -	expected_fd[0] = fda->entries[2].fd;
>  
>  	pr_debug("\nfiltering all but fda->entries[2]:");
>  	fdarray__fprintf_prefix(fda, "before", stderr);
> @@ -66,17 +66,9 @@ int test__fdarray__filter(struct test *test __maybe_unused, int subtest __maybe_
>  		goto out_delete;
>  	}
>  
> -	if (fda->entries[0].fd != expected_fd[0]) {
> -		pr_debug("\nfda->entries[0].fd=%d != %d\n",
> -			 fda->entries[0].fd, expected_fd[0]);
> -		goto out_delete;
> -	}
> -
>  	fdarray__init_revents(fda, POLLHUP);
>  	fda->entries[0].revents = POLLIN;
> -	expected_fd[0] = fda->entries[0].fd;
>  	fda->entries[3].revents = POLLIN;
> -	expected_fd[1] = fda->entries[3].fd;
>  
>  	pr_debug("\nfiltering all but (fda->entries[0], fda->entries[3]):");
>  	fdarray__fprintf_prefix(fda, "before", stderr);
> @@ -88,14 +80,6 @@ int test__fdarray__filter(struct test *test __maybe_unused, int subtest __maybe_
>  		goto out_delete;
>  	}
>  
> -	for (fd = 0; fd < 2; ++fd) {
> -		if (fda->entries[fd].fd != expected_fd[fd]) {
> -			pr_debug("\nfda->entries[%d].fd=%d != %d\n", fd,
> -				 fda->entries[fd].fd, expected_fd[fd]);
> -			goto out_delete;
> -		}
> -	}
> -
>  	pr_debug("\n");
>  
>  	err = 0;
> 

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 09/13] perf stat: implement control commands handling
  2020-06-24 13:39     ` Alexey Budankov
@ 2020-06-25 12:12       ` Jiri Olsa
  2020-06-25 14:52         ` Alexey Budankov
  0 siblings, 1 reply; 49+ messages in thread
From: Jiri Olsa @ 2020-06-25 12:12 UTC (permalink / raw)
  To: Alexey Budankov
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Wed, Jun 24, 2020 at 04:39:11PM +0300, Alexey Budankov wrote:
> 
> 
> On 23.06.2020 17:54, Jiri Olsa wrote:
> > On Wed, Jun 17, 2020 at 11:41:30AM +0300, Alexey Budankov wrote:
> >>
> >> Implement handling of 'enable' and 'disable' control commands
> >> coming from control file descriptor. process_evlist() function
> >> checks for events on control fds and makes required operations.
> >> If poll event splits initiated timeout interval then the reminder
> >> is calculated and still waited in the following poll() syscall.
> >>
> >> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
> >> ---
> >>  tools/perf/builtin-stat.c | 67 +++++++++++++++++++++++++++++----------
> >>  1 file changed, 50 insertions(+), 17 deletions(-)
> >>
> >> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> >> index f88d5ee55022..cc56d71a3ed5 100644
> >> --- a/tools/perf/builtin-stat.c
> >> +++ b/tools/perf/builtin-stat.c
> >> @@ -492,6 +492,31 @@ static bool process_timeout(int timeout, unsigned int interval, int *times)
> >>  	return print_interval(interval, times);
> >>  }
> >>  
> >> +static bool process_evlist(struct evlist *evlist, unsigned int interval, int *times)
> >> +{
> >> +	bool stop = false;
> >> +	enum evlist_ctl_cmd cmd = EVLIST_CTL_CMD_UNSUPPORTED;
> >> +
> >> +	if (evlist__ctlfd_process(evlist, &cmd) > 0) {
> >> +		switch (cmd) {
> >> +		case EVLIST_CTL_CMD_ENABLE:
> >> +			pr_info(EVLIST_ENABLED_MSG);
> >> +			stop = print_interval(interval, times);
> > 
> > why is interval printed in here?
> > 
> >> +			break;
> >> +		case EVLIST_CTL_CMD_DISABLE:
> >> +			stop = print_interval(interval, times);
> > 
> > and here?
> > 
> > it should be called from the main loop when the interval time is elapsed no?
> 
> It is called from the main loop too and it is also additionally called here
> to provide indication and counter values on commands processing times.

so it prints interval out of order?

jirka


^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 09/13] perf stat: implement control commands handling
  2020-06-24 14:10     ` Alexey Budankov
@ 2020-06-25 12:14       ` Jiri Olsa
  2020-06-25 14:58         ` Alexey Budankov
  0 siblings, 1 reply; 49+ messages in thread
From: Jiri Olsa @ 2020-06-25 12:14 UTC (permalink / raw)
  To: Alexey Budankov
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Wed, Jun 24, 2020 at 05:10:10PM +0300, Alexey Budankov wrote:
> 
> On 23.06.2020 17:54, Jiri Olsa wrote:
> > On Wed, Jun 17, 2020 at 11:41:30AM +0300, Alexey Budankov wrote:
> > 
> > SNIP
> > 
> >>  
> >>  	while (1) {
> >>  		if (forks)
> >> @@ -581,8 +617,17 @@ static int dispatch_events(bool forks, int timeout, int interval, int *times, st
> >>  		if (done || stop || child)
> >>  			break;
> >>  
> >> -		nanosleep(ts, NULL);
> >> -		stop = process_timeout(timeout, interval, times);
> >> +		clock_gettime(CLOCK_MONOTONIC, &time_start);
> >> +		if (!(evlist__poll(evsel_list, time_to_sleep) > 0)) { /* poll timeout or EINTR */
> >> +			stop = process_timeout(timeout, interval, times);
> >> +			time_to_sleep = sleep_time;
> >> +		} else { /* fd revent */
> >> +			stop = process_evlist(evsel_list, interval, times);
> >> +			clock_gettime(CLOCK_MONOTONIC, &time_stop);
> >> +			diff_timespec(&time_diff, &time_stop, &time_start);
> >> +			time_to_sleep -= time_diff.tv_sec * MSEC_PER_SEC +
> >> +					time_diff.tv_nsec / NSEC_PER_MSEC;
> > 
> > should we check time_to_sleep > time_diff first?
> 
> Probably and if time_diff > time_to_sleep then time_to_sleep = 0 ?

or extra call to process_timeout? if we dont want to call evlist_poll
with 0 timeout

jirka

> 
> ~Alexey
> 
> > 
> > jirka
> > 
> 


^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 04/13] perf stat: factor out body of event handling loop for system wide
  2020-06-24 14:27     ` Alexey Budankov
@ 2020-06-25 12:17       ` Jiri Olsa
  2020-06-25 16:01         ` Alexey Budankov
  0 siblings, 1 reply; 49+ messages in thread
From: Jiri Olsa @ 2020-06-25 12:17 UTC (permalink / raw)
  To: Alexey Budankov
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Wed, Jun 24, 2020 at 05:27:41PM +0300, Alexey Budankov wrote:
> 
> On 23.06.2020 17:56, Jiri Olsa wrote:
> > On Wed, Jun 17, 2020 at 11:37:43AM +0300, Alexey Budankov wrote:
> >>
> >> Introduce process_timeout() and process_interval() functions that
> >> factor out body of event handling loop for attach and system wide
> >> monitoring use cases.
> >>
> >> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
> >> ---
> >>  tools/perf/builtin-stat.c | 28 ++++++++++++++++++++--------
> >>  1 file changed, 20 insertions(+), 8 deletions(-)
> >>
> >> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> >> index 9be020e0098a..31f7ccf9537b 100644
> >> --- a/tools/perf/builtin-stat.c
> >> +++ b/tools/perf/builtin-stat.c
> >> @@ -475,6 +475,23 @@ static void process_interval(void)
> >>  	print_counters(&rs, 0, NULL);
> >>  }
> >>  
> >> +static bool print_interval(unsigned int interval, int *times)
> >> +{
> >> +	if (interval) {
> >> +		process_interval();
> >> +		if (interval_count && !(--(*times)))
> >> +			return true;
> >> +	}
> >> +	return false;
> >> +}
> >> +
> >> +static bool process_timeout(int timeout, unsigned int interval, int *times)
> >> +{
> >> +	if (timeout)
> >> +		return true;
> >> +	return print_interval(interval, times);
> >> +}
> > 
> > I think it's confusing to keep this together, that
> > process_timeout triggers also interval processing
> > 
> > I think you can keep the timeout separated from interval
> > processing and rename the print_interval to process_interval
> > and process_interval to __process_interval
> 
> Well, ok.
> 
> I will rename process_interval() to __process_interval() and
> then print_interval() to process_interval().
> 
> Regarding timeout let's have it like this:
> 
> static bool process_timeout(int timeout)
> {
> 	return timeout ? true : false;
> }

can't this just stay as value check after finished poll?

	if (timeout)
		break;

and then separate call to process_interval(interval, times)?

jirka

> 
> static bool process_timing_settings(int timeout, unsigned int interval, int *times)
> {
>         bool res = process_timeout(timeout);
>         if (!res)
> 		res = process_interval(interval, times);
> 	return res; 
> }
> 
> Ok?
> 
> ~Alexey
> 
> > 
> > jirka
> > 
> >> +
> >>  static void enable_counters(void)
> >>  {
> >>  	if (stat_config.initial_delay)
> >> @@ -611,6 +628,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
> >>  	struct affinity affinity;
> >>  	int i, cpu;
> >>  	bool second_pass = false;
> >> +	bool stop = false;
> >>  
> >>  	if (interval) {
> >>  		ts.tv_sec  = interval / USEC_PER_MSEC;
> >> @@ -805,17 +823,11 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
> >>  			psignal(WTERMSIG(status), argv[0]);
> >>  	} else {
> >>  		enable_counters();
> >> -		while (!done) {
> >> +		while (!done && !stop) {
> >>  			nanosleep(&ts, NULL);
> >>  			if (!is_target_alive(&target, evsel_list->core.threads))
> >>  				break;
> >> -			if (timeout)
> >> -				break;
> >> -			if (interval) {
> >> -				process_interval();
> >> -				if (interval_count && !(--times))
> >> -					break;
> >> -			}
> >> +			stop = process_timeout(timeout, interval, &times);
> >>  		}
> >>  	}
> >>  
> >> -- 
> >> 2.24.1
> >>
> >>
> > 
> 


^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 09/13] perf stat: implement control commands handling
  2020-06-25 12:12       ` Jiri Olsa
@ 2020-06-25 14:52         ` Alexey Budankov
  0 siblings, 0 replies; 49+ messages in thread
From: Alexey Budankov @ 2020-06-25 14:52 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On 25.06.2020 15:12, Jiri Olsa wrote:
> On Wed, Jun 24, 2020 at 04:39:11PM +0300, Alexey Budankov wrote:
>>
>>
>> On 23.06.2020 17:54, Jiri Olsa wrote:
>>> On Wed, Jun 17, 2020 at 11:41:30AM +0300, Alexey Budankov wrote:
>>>>
>>>> Implement handling of 'enable' and 'disable' control commands
>>>> coming from control file descriptor. process_evlist() function
>>>> checks for events on control fds and makes required operations.
>>>> If poll event splits initiated timeout interval then the reminder
>>>> is calculated and still waited in the following poll() syscall.
>>>>
>>>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
>>>> ---
>>>>  tools/perf/builtin-stat.c | 67 +++++++++++++++++++++++++++++----------
>>>>  1 file changed, 50 insertions(+), 17 deletions(-)
>>>>
>>>> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
>>>> index f88d5ee55022..cc56d71a3ed5 100644
>>>> --- a/tools/perf/builtin-stat.c
>>>> +++ b/tools/perf/builtin-stat.c
>>>> @@ -492,6 +492,31 @@ static bool process_timeout(int timeout, unsigned int interval, int *times)
>>>>  	return print_interval(interval, times);
>>>>  }
>>>>  
>>>> +static bool process_evlist(struct evlist *evlist, unsigned int interval, int *times)
>>>> +{
>>>> +	bool stop = false;
>>>> +	enum evlist_ctl_cmd cmd = EVLIST_CTL_CMD_UNSUPPORTED;
>>>> +
>>>> +	if (evlist__ctlfd_process(evlist, &cmd) > 0) {
>>>> +		switch (cmd) {
>>>> +		case EVLIST_CTL_CMD_ENABLE:
>>>> +			pr_info(EVLIST_ENABLED_MSG);
>>>> +			stop = print_interval(interval, times);
>>>
>>> why is interval printed in here?
>>>
>>>> +			break;
>>>> +		case EVLIST_CTL_CMD_DISABLE:
>>>> +			stop = print_interval(interval, times);
>>>
>>> and here?
>>>
>>> it should be called from the main loop when the interval time is elapsed no?
>>
>> It is called from the main loop too and it is also additionally called here
>> to provide indication and counter values on commands processing times.
> 
> so it prints interval out of order?

Looks like it does. The only issue with it I see is change in times value.

~Alexey

> 
> jirka
> 

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 09/13] perf stat: implement control commands handling
  2020-06-25 12:14       ` Jiri Olsa
@ 2020-06-25 14:58         ` Alexey Budankov
  0 siblings, 0 replies; 49+ messages in thread
From: Alexey Budankov @ 2020-06-25 14:58 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel


On 25.06.2020 15:14, Jiri Olsa wrote:
> On Wed, Jun 24, 2020 at 05:10:10PM +0300, Alexey Budankov wrote:
>>
>> On 23.06.2020 17:54, Jiri Olsa wrote:
>>> On Wed, Jun 17, 2020 at 11:41:30AM +0300, Alexey Budankov wrote:
>>>
>>> SNIP
>>>
>>>>  
>>>>  	while (1) {
>>>>  		if (forks)
>>>> @@ -581,8 +617,17 @@ static int dispatch_events(bool forks, int timeout, int interval, int *times, st
>>>>  		if (done || stop || child)
>>>>  			break;
>>>>  
>>>> -		nanosleep(ts, NULL);
>>>> -		stop = process_timeout(timeout, interval, times);
>>>> +		clock_gettime(CLOCK_MONOTONIC, &time_start);
>>>> +		if (!(evlist__poll(evsel_list, time_to_sleep) > 0)) { /* poll timeout or EINTR */
>>>> +			stop = process_timeout(timeout, interval, times);
>>>> +			time_to_sleep = sleep_time;
>>>> +		} else { /* fd revent */
>>>> +			stop = process_evlist(evsel_list, interval, times);
>>>> +			clock_gettime(CLOCK_MONOTONIC, &time_stop);
>>>> +			diff_timespec(&time_diff, &time_stop, &time_start);
>>>> +			time_to_sleep -= time_diff.tv_sec * MSEC_PER_SEC +
>>>> +					time_diff.tv_nsec / NSEC_PER_MSEC;
>>>
>>> should we check time_to_sleep > time_diff first?
>>
>> Probably and if time_diff > time_to_sleep then time_to_sleep = 0 ?
> 
> or extra call to process_timeout? if we dont want to call evlist_poll
> with 0 timeout

poll() man page says it is ok to call poll with 0 timeout so 
process_timeout() and initialization of time_to_sleep will be
done in common flow.

~Alexey

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 04/13] perf stat: factor out body of event handling loop for system wide
  2020-06-25 12:17       ` Jiri Olsa
@ 2020-06-25 16:01         ` Alexey Budankov
  2020-06-25 17:13           ` Jiri Olsa
  0 siblings, 1 reply; 49+ messages in thread
From: Alexey Budankov @ 2020-06-25 16:01 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel


On 25.06.2020 15:17, Jiri Olsa wrote:
> On Wed, Jun 24, 2020 at 05:27:41PM +0300, Alexey Budankov wrote:
>>
>> On 23.06.2020 17:56, Jiri Olsa wrote:
>>> On Wed, Jun 17, 2020 at 11:37:43AM +0300, Alexey Budankov wrote:
>>>>
>>>> Introduce process_timeout() and process_interval() functions that
>>>> factor out body of event handling loop for attach and system wide
>>>> monitoring use cases.
>>>>
>>>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
>>>> ---
>>>>  tools/perf/builtin-stat.c | 28 ++++++++++++++++++++--------
>>>>  1 file changed, 20 insertions(+), 8 deletions(-)
>>>>
>>>> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
>>>> index 9be020e0098a..31f7ccf9537b 100644
>>>> --- a/tools/perf/builtin-stat.c
>>>> +++ b/tools/perf/builtin-stat.c
>>>> @@ -475,6 +475,23 @@ static void process_interval(void)
>>>>  	print_counters(&rs, 0, NULL);
>>>>  }
>>>>  
>>>> +static bool print_interval(unsigned int interval, int *times)
>>>> +{
>>>> +	if (interval) {
>>>> +		process_interval();
>>>> +		if (interval_count && !(--(*times)))
>>>> +			return true;
>>>> +	}
>>>> +	return false;
>>>> +}
>>>> +
>>>> +static bool process_timeout(int timeout, unsigned int interval, int *times)
>>>> +{
>>>> +	if (timeout)
>>>> +		return true;
>>>> +	return print_interval(interval, times);
>>>> +}
>>>
>>> I think it's confusing to keep this together, that
>>> process_timeout triggers also interval processing
>>>
>>> I think you can keep the timeout separated from interval
>>> processing and rename the print_interval to process_interval
>>> and process_interval to __process_interval
>>
>> Well, ok.
>>
>> I will rename process_interval() to __process_interval() and
>> then print_interval() to process_interval().
>>
>> Regarding timeout let's have it like this:
>>
>> static bool process_timeout(int timeout)
>> {
>> 	return timeout ? true : false;
>> }
> 
> can't this just stay as value check after finished poll?
> 
> 	if (timeout)
> 		break;
> 
> and then separate call to process_interval(interval, times)?

Like this? Still makes sense to have it in a single function.

static bool process_timing_settings(int timeout, unsigned int interval, int *times)
{
	bool res = timeout ? true : false;
        if (!res)
 		res = process_interval(interval, times);
 	return res;
}

~Alexey

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 12/13] perf record: implement control commands handling
  2020-06-24 14:55       ` Alexey Budankov
@ 2020-06-25 17:07         ` Jiri Olsa
  0 siblings, 0 replies; 49+ messages in thread
From: Jiri Olsa @ 2020-06-25 17:07 UTC (permalink / raw)
  To: Alexey Budankov
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Wed, Jun 24, 2020 at 05:55:02PM +0300, Alexey Budankov wrote:
> 
> On 24.06.2020 17:00, Alexey Budankov wrote:
> > 
> > On 23.06.2020 17:54, Jiri Olsa wrote:
> >> On Wed, Jun 17, 2020 at 11:43:58AM +0300, Alexey Budankov wrote:
> >>>
> >>> Implement handling of 'enable' and 'disable' control commands
> >>> coming from control file descriptor.
> >>>
> >>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
> >>> ---
> >>>  tools/perf/builtin-record.c | 16 ++++++++++++++++
> >>>  1 file changed, 16 insertions(+)
> >>>
> >>> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> >>> index d0b29a1070a0..0394e068dde8 100644
> >>> --- a/tools/perf/builtin-record.c
> >>> +++ b/tools/perf/builtin-record.c
> >>> @@ -1527,6 +1527,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
> >>>  	bool disabled = false, draining = false;
> >>>  	int fd;
> >>>  	float ratio = 0;
> >>> +	enum evlist_ctl_cmd cmd = EVLIST_CTL_CMD_UNSUPPORTED;
> >>>  
> >>>  	atexit(record__sig_exit);
> >>>  	signal(SIGCHLD, sig_handler);
> >>> @@ -1830,6 +1831,21 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
> >>>  				alarm(rec->switch_output.time);
> >>>  		}
> >>>  
> >>> +		if (evlist__ctlfd_process(rec->evlist, &cmd) > 0) {
> >>> +			switch (cmd) {
> >>> +			case EVLIST_CTL_CMD_ENABLE:
> >>> +				pr_info(EVLIST_ENABLED_MSG);
> >>> +				break;
> >>> +			case EVLIST_CTL_CMD_DISABLE:
> >>> +				pr_info(EVLIST_DISABLED_MSG);
> >>> +				break;
> >>> +			case EVLIST_CTL_CMD_ACK:
> >>> +			case EVLIST_CTL_CMD_UNSUPPORTED:
> >>> +			default:
> >>> +				break;
> >>> +			}
> >>> +		}
> >>
> >> so there's still the filter call like:
> >>
> >>                         if (evlist__filter_pollfd(rec->evlist, POLLERR | POLLHUP) == 0)
> >>                                 draining = true;
> >>
> >> it will never be 0 if the control fds are stil alive no?
> > 
> > Due to change in filter_pollfd() and preceding evlist__ctlfd_process() call
> > now control fd is not counted by filter_pollfd().
> And evlist__ctlfd_process() still should be called second time right
> after evlist_poll() but prior filter_polfd().

aaah it's set to zero in here:

        if (entries[ctlfd_pos].revents & (POLLHUP | POLLERR))
                evlist__finalize_ctlfd(evlist);
        else
                entries[ctlfd_pos].revents = 0;

yea, that's bad.. another reason to call it a hack

jirka

> 
> ~Alexey
> 
> > 
> > However event fds with .revents == 0 are not counted either and this breaks
> > the algorithm thus something more is still required to cover this gap.
> > 
> > ~Alexey
> > 
> >>
> >> jirka
> >>
> 


^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 04/13] perf stat: factor out body of event handling loop for system wide
  2020-06-25 16:01         ` Alexey Budankov
@ 2020-06-25 17:13           ` Jiri Olsa
  2020-06-25 18:43             ` Alexey Budankov
  0 siblings, 1 reply; 49+ messages in thread
From: Jiri Olsa @ 2020-06-25 17:13 UTC (permalink / raw)
  To: Alexey Budankov
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Thu, Jun 25, 2020 at 07:01:08PM +0300, Alexey Budankov wrote:

SNIP

> >>
> >> Well, ok.
> >>
> >> I will rename process_interval() to __process_interval() and
> >> then print_interval() to process_interval().
> >>
> >> Regarding timeout let's have it like this:
> >>
> >> static bool process_timeout(int timeout)
> >> {
> >> 	return timeout ? true : false;
> >> }
> > 
> > can't this just stay as value check after finished poll?
> > 
> > 	if (timeout)
> > 		break;
> > 
> > and then separate call to process_interval(interval, times)?
> 
> Like this? Still makes sense to have it in a single function.
> 
> static bool process_timing_settings(int timeout, unsigned int interval, int *times)
> {
> 	bool res = timeout ? true : false;
>         if (!res)
>  		res = process_interval(interval, times);
>  	return res;
> }

I don't see the connection between timeout and interval
IMO this just complicates things, is there a problem to
keep it separated as it is now?

jirka

> 
> ~Alexey
> 


^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 01/13] tools/libperf: avoid moving of fds at fdarray__filter() call
  2020-06-24 17:19   ` Alexey Budankov
@ 2020-06-25 17:14     ` Jiri Olsa
  2020-06-25 19:32       ` Alexey Budankov
  0 siblings, 1 reply; 49+ messages in thread
From: Jiri Olsa @ 2020-06-25 17:14 UTC (permalink / raw)
  To: Alexey Budankov
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Wed, Jun 24, 2020 at 08:19:32PM +0300, Alexey Budankov wrote:
> 
> On 17.06.2020 11:35, Alexey Budankov wrote:
> > 
> > Skip fds with zeroed revents field from count and avoid fds moving
> > at fdarray__filter() call so fds indices returned by fdarray__add()
> > call stay the same and can be used for direct access and processing
> > of fd revents status field at entries array of struct fdarray object.
> > 
> > Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
> > ---
> >  tools/lib/api/fd/array.c   | 11 +++++------
> >  tools/perf/tests/fdarray.c | 20 ++------------------
> >  2 files changed, 7 insertions(+), 24 deletions(-)
> > 
> > diff --git a/tools/lib/api/fd/array.c b/tools/lib/api/fd/array.c
> > index 58d44d5eee31..97843a837370 100644
> > --- a/tools/lib/api/fd/array.c
> > +++ b/tools/lib/api/fd/array.c
> > @@ -93,22 +93,21 @@ int fdarray__filter(struct fdarray *fda, short revents,
> >  		return 0;
> >  
> >  	for (fd = 0; fd < fda->nr; ++fd) {
> > +		if (!fda->entries[fd].revents)
> > +			continue;
> > +
> 
> So it looks like this condition also filters out non signaling events fds, not only
> control and others fds, and this should be somehow avoided so such event related fds
> would be counted. Several options have been proposed so far:
> 
> 1) Explicit typing of fds via API extension and filtering based on the types:
>    a) with separate fdarray__add_stat() call
>    b) with type arg of existing fdarray__add() call
>    c) various memory management design is possible
> 
> 2) Playing tricks with fd positions inside entries and assumptions on fdarray API calls ordering
>    - looks more like a hack than a designed solution
> 
> 3) Rewrite of fdarray class to allocate separate object for every added fds
>    - can be replaced with nonscrewing of fds by __filter()
> 
> 4) Distinct between fds types at fdarray__filter() using .revents == 0 condition
>    - seems to have corner cases and thus not applicable
> 
> 5) Extension of fdarray__poll(, *arg_ptr, arg_size) with arg of fds array to atomically poll
>    on fdarray_add()-ed fds and external arg fds and then external arg fds processing
> 
> 6) Rewrite of fdarray class on epoll() call basis
>    - introduces new scalability restrictions for Perf tool

hum, how many fds for polling do you expect in your workloads?

jirka


^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 04/13] perf stat: factor out body of event handling loop for system wide
  2020-06-25 17:13           ` Jiri Olsa
@ 2020-06-25 18:43             ` Alexey Budankov
  0 siblings, 0 replies; 49+ messages in thread
From: Alexey Budankov @ 2020-06-25 18:43 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel


On 25.06.2020 20:13, Jiri Olsa wrote:
> On Thu, Jun 25, 2020 at 07:01:08PM +0300, Alexey Budankov wrote:
> 
> SNIP
> 
>>>>
>>>> Well, ok.
>>>>
>>>> I will rename process_interval() to __process_interval() and
>>>> then print_interval() to process_interval().
>>>>
>>>> Regarding timeout let's have it like this:
>>>>
>>>> static bool process_timeout(int timeout)
>>>> {
>>>> 	return timeout ? true : false;
>>>> }
>>>
>>> can't this just stay as value check after finished poll?
>>>
>>> 	if (timeout)
>>> 		break;
>>>
>>> and then separate call to process_interval(interval, times)?
>>
>> Like this? Still makes sense to have it in a single function.
>>
>> static bool process_timing_settings(int timeout, unsigned int interval, int *times)
>> {
>> 	bool res = timeout ? true : false;
>>         if (!res)
>>  		res = process_interval(interval, times);
>>  	return res;
>> }
> 
> I don't see the connection between timeout and interval
> IMO this just complicates things, is there a problem to
> keep it separated as it is now?

Not a problem. Can duplicate it in dispatch_events().

~Alexey

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 01/13] tools/libperf: avoid moving of fds at fdarray__filter() call
  2020-06-25 17:14     ` Jiri Olsa
@ 2020-06-25 19:32       ` Alexey Budankov
  2020-06-26  9:37         ` Jiri Olsa
  0 siblings, 1 reply; 49+ messages in thread
From: Alexey Budankov @ 2020-06-25 19:32 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel


On 25.06.2020 20:14, Jiri Olsa wrote:
> On Wed, Jun 24, 2020 at 08:19:32PM +0300, Alexey Budankov wrote:
>>
>> On 17.06.2020 11:35, Alexey Budankov wrote:
>>>
>>> Skip fds with zeroed revents field from count and avoid fds moving
>>> at fdarray__filter() call so fds indices returned by fdarray__add()
>>> call stay the same and can be used for direct access and processing
>>> of fd revents status field at entries array of struct fdarray object.
>>>
>>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
>>> ---
>>>  tools/lib/api/fd/array.c   | 11 +++++------
>>>  tools/perf/tests/fdarray.c | 20 ++------------------
>>>  2 files changed, 7 insertions(+), 24 deletions(-)
>>>
>>> diff --git a/tools/lib/api/fd/array.c b/tools/lib/api/fd/array.c
>>> index 58d44d5eee31..97843a837370 100644
>>> --- a/tools/lib/api/fd/array.c
>>> +++ b/tools/lib/api/fd/array.c
>>> @@ -93,22 +93,21 @@ int fdarray__filter(struct fdarray *fda, short revents,
>>>  		return 0;
>>>  
>>>  	for (fd = 0; fd < fda->nr; ++fd) {
>>> +		if (!fda->entries[fd].revents)
>>> +			continue;
>>> +
>>
>> So it looks like this condition also filters out non signaling events fds, not only
>> control and others fds, and this should be somehow avoided so such event related fds
>> would be counted. Several options have been proposed so far:
>>
>> 1) Explicit typing of fds via API extension and filtering based on the types:
>>    a) with separate fdarray__add_stat() call
>>    b) with type arg of existing fdarray__add() call
>>    c) various memory management design is possible
>>
>> 2) Playing tricks with fd positions inside entries and assumptions on fdarray API calls ordering
>>    - looks more like a hack than a designed solution
>>
>> 3) Rewrite of fdarray class to allocate separate object for every added fds
>>    - can be replaced with nonscrewing of fds by __filter()
>>
>> 4) Distinct between fds types at fdarray__filter() using .revents == 0 condition
>>    - seems to have corner cases and thus not applicable
>>
>> 5) Extension of fdarray__poll(, *arg_ptr, arg_size) with arg of fds array to atomically poll
>>    on fdarray_add()-ed fds and external arg fds and then external arg fds processing
>>
>> 6) Rewrite of fdarray class on epoll() call basis
>>    - introduces new scalability restrictions for Perf tool
> 
> hum, how many fds for polling do you expect in your workloads?

Currently it is several hundreds so default of 1K is easily hit and 
"Profile a Large Number of PMU Events on Multi-Core Systems" section [1]
recommends:

soft nofile 65535
hard nofile 65535

for for /etc/security/limits.conf settings.

~Alexey

[1] https://software.intel.com/content/www/us/en/develop/documentation/vtune-cookbook/top/configuration-recipes/profiling-hardware-without-sampling-drivers.html

> 
> jirka
> 

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 01/13] tools/libperf: avoid moving of fds at fdarray__filter() call
  2020-06-25 19:32       ` Alexey Budankov
@ 2020-06-26  9:37         ` Jiri Olsa
  2020-06-26 10:06           ` Alexey Budankov
  0 siblings, 1 reply; 49+ messages in thread
From: Jiri Olsa @ 2020-06-26  9:37 UTC (permalink / raw)
  To: Alexey Budankov
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Thu, Jun 25, 2020 at 10:32:29PM +0300, Alexey Budankov wrote:
> 
> On 25.06.2020 20:14, Jiri Olsa wrote:
> > On Wed, Jun 24, 2020 at 08:19:32PM +0300, Alexey Budankov wrote:
> >>
> >> On 17.06.2020 11:35, Alexey Budankov wrote:
> >>>
> >>> Skip fds with zeroed revents field from count and avoid fds moving
> >>> at fdarray__filter() call so fds indices returned by fdarray__add()
> >>> call stay the same and can be used for direct access and processing
> >>> of fd revents status field at entries array of struct fdarray object.
> >>>
> >>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
> >>> ---
> >>>  tools/lib/api/fd/array.c   | 11 +++++------
> >>>  tools/perf/tests/fdarray.c | 20 ++------------------
> >>>  2 files changed, 7 insertions(+), 24 deletions(-)
> >>>
> >>> diff --git a/tools/lib/api/fd/array.c b/tools/lib/api/fd/array.c
> >>> index 58d44d5eee31..97843a837370 100644
> >>> --- a/tools/lib/api/fd/array.c
> >>> +++ b/tools/lib/api/fd/array.c
> >>> @@ -93,22 +93,21 @@ int fdarray__filter(struct fdarray *fda, short revents,
> >>>  		return 0;
> >>>  
> >>>  	for (fd = 0; fd < fda->nr; ++fd) {
> >>> +		if (!fda->entries[fd].revents)
> >>> +			continue;
> >>> +
> >>
> >> So it looks like this condition also filters out non signaling events fds, not only
> >> control and others fds, and this should be somehow avoided so such event related fds
> >> would be counted. Several options have been proposed so far:
> >>
> >> 1) Explicit typing of fds via API extension and filtering based on the types:
> >>    a) with separate fdarray__add_stat() call
> >>    b) with type arg of existing fdarray__add() call
> >>    c) various memory management design is possible
> >>
> >> 2) Playing tricks with fd positions inside entries and assumptions on fdarray API calls ordering
> >>    - looks more like a hack than a designed solution
> >>
> >> 3) Rewrite of fdarray class to allocate separate object for every added fds
> >>    - can be replaced with nonscrewing of fds by __filter()
> >>
> >> 4) Distinct between fds types at fdarray__filter() using .revents == 0 condition
> >>    - seems to have corner cases and thus not applicable
> >>
> >> 5) Extension of fdarray__poll(, *arg_ptr, arg_size) with arg of fds array to atomically poll
> >>    on fdarray_add()-ed fds and external arg fds and then external arg fds processing
> >>
> >> 6) Rewrite of fdarray class on epoll() call basis
> >>    - introduces new scalability restrictions for Perf tool
> > 
> > hum, how many fds for polling do you expect in your workloads?
> 
> Currently it is several hundreds so default of 1K is easily hit and 
> "Profile a Large Number of PMU Events on Multi-Core Systems" section [1]
> recommends:
> 
> soft nofile 65535
> hard nofile 65535

I'm confused, are you talking about file descriptors limit now?
this wont be affected by epoll change.. what do I miss?

I thought your concern was fs.epoll.max_user_watches, which has
default value that seems to be enough:

	$ cat /proc/sys/fs/epoll/max_user_watches
	3169996

jirka


> 
> for for /etc/security/limits.conf settings.
> 
> ~Alexey
> 
> [1] https://software.intel.com/content/www/us/en/develop/documentation/vtune-cookbook/top/configuration-recipes/profiling-hardware-without-sampling-drivers.html
> 
> > 
> > jirka
> > 
> 


^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 01/13] tools/libperf: avoid moving of fds at fdarray__filter() call
  2020-06-26  9:37         ` Jiri Olsa
@ 2020-06-26 10:06           ` Alexey Budankov
  2020-06-29 15:11             ` Alexey Budankov
  0 siblings, 1 reply; 49+ messages in thread
From: Alexey Budankov @ 2020-06-26 10:06 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel


On 26.06.2020 12:37, Jiri Olsa wrote:
> On Thu, Jun 25, 2020 at 10:32:29PM +0300, Alexey Budankov wrote:
>>
>> On 25.06.2020 20:14, Jiri Olsa wrote:
>>> On Wed, Jun 24, 2020 at 08:19:32PM +0300, Alexey Budankov wrote:
>>>>
>>>> On 17.06.2020 11:35, Alexey Budankov wrote:
>>>>>
>>>>> Skip fds with zeroed revents field from count and avoid fds moving
>>>>> at fdarray__filter() call so fds indices returned by fdarray__add()
>>>>> call stay the same and can be used for direct access and processing
>>>>> of fd revents status field at entries array of struct fdarray object.
>>>>>
>>>>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
>>>>> ---
>>>>>  tools/lib/api/fd/array.c   | 11 +++++------
>>>>>  tools/perf/tests/fdarray.c | 20 ++------------------
>>>>>  2 files changed, 7 insertions(+), 24 deletions(-)
>>>>>
>>>>> diff --git a/tools/lib/api/fd/array.c b/tools/lib/api/fd/array.c
>>>>> index 58d44d5eee31..97843a837370 100644
>>>>> --- a/tools/lib/api/fd/array.c
>>>>> +++ b/tools/lib/api/fd/array.c
>>>>> @@ -93,22 +93,21 @@ int fdarray__filter(struct fdarray *fda, short revents,
>>>>>  		return 0;
>>>>>  
>>>>>  	for (fd = 0; fd < fda->nr; ++fd) {
>>>>> +		if (!fda->entries[fd].revents)
>>>>> +			continue;
>>>>> +
>>>>
>>>> So it looks like this condition also filters out non signaling events fds, not only
>>>> control and others fds, and this should be somehow avoided so such event related fds
>>>> would be counted. Several options have been proposed so far:
>>>>
>>>> 1) Explicit typing of fds via API extension and filtering based on the types:
>>>>    a) with separate fdarray__add_stat() call
>>>>    b) with type arg of existing fdarray__add() call
>>>>    c) various memory management design is possible
>>>>
>>>> 2) Playing tricks with fd positions inside entries and assumptions on fdarray API calls ordering
>>>>    - looks more like a hack than a designed solution
>>>>
>>>> 3) Rewrite of fdarray class to allocate separate object for every added fds
>>>>    - can be replaced with nonscrewing of fds by __filter()
>>>>
>>>> 4) Distinct between fds types at fdarray__filter() using .revents == 0 condition
>>>>    - seems to have corner cases and thus not applicable
>>>>
>>>> 5) Extension of fdarray__poll(, *arg_ptr, arg_size) with arg of fds array to atomically poll
>>>>    on fdarray_add()-ed fds and external arg fds and then external arg fds processing
>>>>
>>>> 6) Rewrite of fdarray class on epoll() call basis
>>>>    - introduces new scalability restrictions for Perf tool
>>>
>>> hum, how many fds for polling do you expect in your workloads?
>>
>> Currently it is several hundreds so default of 1K is easily hit and 
>> "Profile a Large Number of PMU Events on Multi-Core Systems" section [1]
>> recommends:
>>
>> soft nofile 65535
>> hard nofile 65535
> 
> I'm confused, are you talking about file descriptors limit now?
> this wont be affected by epoll change.. what do I miss?

Currently there is already uname -n limit on the amount of open file descriptors
and Perf tool process is affected by that limit.

Moving to epoll() will impose one more max_user_watches limit and that can additionally
confine Perf applicability even though default value on some machines currently
is high enough.

~Alexey

> 
> I thought your concern was fs.epoll.max_user_watches, which has
> default value that seems to be enough:
> 
> 	$ cat /proc/sys/fs/epoll/max_user_watches
> 	3169996
> 
> jirka
> 
> 
>>
>> for for /etc/security/limits.conf settings.
>>
>> ~Alexey
>>
>> [1] https://software.intel.com/content/www/us/en/develop/documentation/vtune-cookbook/top/configuration-recipes/profiling-hardware-without-sampling-drivers.html
>>
>>>
>>> jirka
>>>
>>
> 

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 01/13] tools/libperf: avoid moving of fds at fdarray__filter() call
  2020-06-26 10:06           ` Alexey Budankov
@ 2020-06-29 15:11             ` Alexey Budankov
  2020-06-29 19:17               ` Jiri Olsa
  0 siblings, 1 reply; 49+ messages in thread
From: Alexey Budankov @ 2020-06-29 15:11 UTC (permalink / raw)
  To: Jiri Olsa, Arnaldo Carvalho de Melo
  Cc: Namhyung Kim, Alexander Shishkin, Peter Zijlstra, Ingo Molnar,
	Andi Kleen, linux-kernel


On 26.06.2020 13:06, Alexey Budankov wrote:
> 
> On 26.06.2020 12:37, Jiri Olsa wrote:
>> On Thu, Jun 25, 2020 at 10:32:29PM +0300, Alexey Budankov wrote:
>>>
>>> On 25.06.2020 20:14, Jiri Olsa wrote:
>>>> On Wed, Jun 24, 2020 at 08:19:32PM +0300, Alexey Budankov wrote:
>>>>>
>>>>> On 17.06.2020 11:35, Alexey Budankov wrote:
>>>>>>
>>>>>> Skip fds with zeroed revents field from count and avoid fds moving
>>>>>> at fdarray__filter() call so fds indices returned by fdarray__add()
>>>>>> call stay the same and can be used for direct access and processing
>>>>>> of fd revents status field at entries array of struct fdarray object.
>>>>>>
>>>>>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
>>>>>> ---
>>>>>>  tools/lib/api/fd/array.c   | 11 +++++------
>>>>>>  tools/perf/tests/fdarray.c | 20 ++------------------
>>>>>>  2 files changed, 7 insertions(+), 24 deletions(-)
>>>>>>
>>>>>> diff --git a/tools/lib/api/fd/array.c b/tools/lib/api/fd/array.c
>>>>>> index 58d44d5eee31..97843a837370 100644
>>>>>> --- a/tools/lib/api/fd/array.c
>>>>>> +++ b/tools/lib/api/fd/array.c
>>>>>> @@ -93,22 +93,21 @@ int fdarray__filter(struct fdarray *fda, short revents,
>>>>>>  		return 0;
>>>>>>  
>>>>>>  	for (fd = 0; fd < fda->nr; ++fd) {
>>>>>> +		if (!fda->entries[fd].revents)
>>>>>> +			continue;
>>>>>> +
>>>>>
>>>>> So it looks like this condition also filters out non signaling events fds, not only
>>>>> control and others fds, and this should be somehow avoided so such event related fds
>>>>> would be counted. Several options have been proposed so far:
>>>>>
>>>>> 1) Explicit typing of fds via API extension and filtering based on the types:
>>>>>    a) with separate fdarray__add_stat() call
>>>>>    b) with type arg of existing fdarray__add() call
>>>>>    c) various memory management design is possible
>>>>>
>>>>> 2) Playing tricks with fd positions inside entries and assumptions on fdarray API calls ordering
>>>>>    - looks more like a hack than a designed solution
>>>>>
>>>>> 3) Rewrite of fdarray class to allocate separate object for every added fds
>>>>>    - can be replaced with nonscrewing of fds by __filter()
>>>>>
>>>>> 4) Distinct between fds types at fdarray__filter() using .revents == 0 condition
>>>>>    - seems to have corner cases and thus not applicable
>>>>>
>>>>> 5) Extension of fdarray__poll(, *arg_ptr, arg_size) with arg of fds array to atomically poll
>>>>>    on fdarray_add()-ed fds and external arg fds and then external arg fds processing
>>>>>
>>>>> 6) Rewrite of fdarray class on epoll() call basis
>>>>>    - introduces new scalability restrictions for Perf tool
>>>>
>>>> hum, how many fds for polling do you expect in your workloads?
>>>
>>> Currently it is several hundreds so default of 1K is easily hit and 
>>> "Profile a Large Number of PMU Events on Multi-Core Systems" section [1]
>>> recommends:
>>>
>>> soft nofile 65535
>>> hard nofile 65535
>>
>> I'm confused, are you talking about file descriptors limit now?
>> this wont be affected by epoll change.. what do I miss?
> 
> Currently there is already uname -n limit on the amount of open file descriptors
> and Perf tool process is affected by that limit.
> 
> Moving to epoll() will impose one more max_user_watches limit and that can additionally
> confine Perf applicability even though default value on some machines currently
> is high enough.

Prior making v9 I would prefer to agree on some design to be implemented in order to
avoid guessing and redundant reiterating.

Options that I see as good balanced ones are 1) or 5), + non screwing of fds to fix
staleness of pos(=fdarray__add()).

Are there any thoughts so far?

~Aleksei

^ permalink raw reply	[flat|nested] 49+ messages in thread

* Re: [PATCH v8 01/13] tools/libperf: avoid moving of fds at fdarray__filter() call
  2020-06-29 15:11             ` Alexey Budankov
@ 2020-06-29 19:17               ` Jiri Olsa
  0 siblings, 0 replies; 49+ messages in thread
From: Jiri Olsa @ 2020-06-29 19:17 UTC (permalink / raw)
  To: Alexey Budankov
  Cc: Arnaldo Carvalho de Melo, Namhyung Kim, Alexander Shishkin,
	Peter Zijlstra, Ingo Molnar, Andi Kleen, linux-kernel

On Mon, Jun 29, 2020 at 06:11:52PM +0300, Alexey Budankov wrote:

SNIP

> >>
> >> I'm confused, are you talking about file descriptors limit now?
> >> this wont be affected by epoll change.. what do I miss?
> > 
> > Currently there is already uname -n limit on the amount of open file descriptors
> > and Perf tool process is affected by that limit.
> > 
> > Moving to epoll() will impose one more max_user_watches limit and that can additionally
> > confine Perf applicability even though default value on some machines currently
> > is high enough.
> 
> Prior making v9 I would prefer to agree on some design to be implemented in order to
> avoid guessing and redundant reiterating.
> 
> Options that I see as good balanced ones are 1) or 5), + non screwing of fds to fix
> staleness of pos(=fdarray__add()).
> 
> Are there any thoughts so far?

let's try it and discuss over the code

jirka


^ permalink raw reply	[flat|nested] 49+ messages in thread

end of thread, other threads:[~2020-06-29 19:17 UTC | newest]

Thread overview: 49+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-06-17  8:30 [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
2020-06-17  8:35 ` [PATCH v8 01/13] tools/libperf: avoid moving of fds at fdarray__filter() call Alexey Budankov
2020-06-24 17:19   ` Alexey Budankov
2020-06-25 17:14     ` Jiri Olsa
2020-06-25 19:32       ` Alexey Budankov
2020-06-26  9:37         ` Jiri Olsa
2020-06-26 10:06           ` Alexey Budankov
2020-06-29 15:11             ` Alexey Budankov
2020-06-29 19:17               ` Jiri Olsa
2020-06-17  8:35 ` [PATCH v8 02/13] perf evlist: introduce control file descriptors Alexey Budankov
2020-06-17  8:36 ` [PATCH v8 03/13] perf evlist: implement control command handling functions Alexey Budankov
2020-06-23 14:56   ` Jiri Olsa
2020-06-23 15:03     ` Arnaldo Carvalho de Melo
2020-06-23 15:14       ` Jiri Olsa
2020-06-24 13:35         ` Alexey Budankov
2020-06-23 14:56   ` Jiri Olsa
2020-06-24 13:20     ` Alexey Budankov
2020-06-17  8:37 ` [PATCH v8 04/13] perf stat: factor out body of event handling loop for system wide Alexey Budankov
2020-06-23 14:56   ` Jiri Olsa
2020-06-24 14:27     ` Alexey Budankov
2020-06-25 12:17       ` Jiri Olsa
2020-06-25 16:01         ` Alexey Budankov
2020-06-25 17:13           ` Jiri Olsa
2020-06-25 18:43             ` Alexey Budankov
2020-06-17  8:38 ` [PATCH v8 05/13] perf stat: move target check to loop control statement Alexey Budankov
2020-06-17  8:39 ` [PATCH v8 06/13] perf stat: factor out body of event handling loop for fork case Alexey Budankov
2020-06-17  8:40 ` [PATCH v8 07/13] perf stat: factor out event handling loop into dispatch_events() Alexey Budankov
2020-06-23 14:56   ` Jiri Olsa
2020-06-24 13:27     ` Alexey Budankov
2020-06-17  8:40 ` [PATCH v8 08/13] perf stat: extend -D,--delay option with -1 value Alexey Budankov
2020-06-17  8:41 ` [PATCH v8 09/13] perf stat: implement control commands handling Alexey Budankov
2020-06-23 14:54   ` Jiri Olsa
2020-06-24 14:10     ` Alexey Budankov
2020-06-25 12:14       ` Jiri Olsa
2020-06-25 14:58         ` Alexey Budankov
2020-06-23 14:54   ` Jiri Olsa
2020-06-24 13:39     ` Alexey Budankov
2020-06-25 12:12       ` Jiri Olsa
2020-06-25 14:52         ` Alexey Budankov
2020-06-17  8:42 ` [PATCH v8 10/13] perf stat: introduce --control fd:ctl-fd[,ack-fd] options Alexey Budankov
2020-06-17  8:42 ` [PATCH v8 11/13] perf record: extend -D,--delay option with -1 value Alexey Budankov
2020-06-17  8:43 ` [PATCH v8 12/13] perf record: implement control commands handling Alexey Budankov
2020-06-23 14:54   ` Jiri Olsa
2020-06-24 14:00     ` Alexey Budankov
2020-06-24 14:55       ` Alexey Budankov
2020-06-25 17:07         ` Jiri Olsa
2020-06-17  8:44 ` [PATCH v8 13/13] perf record: introduce --control fd:ctl-fd[,ack-fd] options Alexey Budankov
2020-06-22  3:38 ` [PATCH v8 00/13] perf: support enable and disable commands in stat and record modes Alexey Budankov
2020-06-22  8:55   ` Jiri Olsa

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).