* [PATCH v33 0/5] Timestamp synchronization of host - guest tracing session
@ 2021-03-25 7:14 Tzvetomir Stoyanov (VMware)
2021-03-25 7:14 ` [PATCH v33 1/5] trace-cmd: Add dummy function to initialize timestamp sync logic Tzvetomir Stoyanov (VMware)
` (4 more replies)
0 siblings, 5 replies; 7+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2021-03-25 7:14 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel, stefano.devenuto99
Basic infrastructure for host - guest timestamp synchronization and a
PoC implementation of PTP-like and KVM algorithms.
The KVM plugin is with higher weight than PTP, it is preferred in case both
are active. KVM is used only if x86-tsc clock is selected for the current
trace, PTP is used for all other cases.
These changes depend on:
"Refactoring and improvements of time sync logic" patch set.
"TSC trace clock to nanosecond conversion" patch set.
v33 changes:
- Check for non-default KVM scaling. If such is detected, fail back to the
ptp algorithm. The problem with the KVM scaling is
Reported-by: Stefano De Venuto <stefano.devenuto99@gmail.com>
v32 changes:
- Reduced the patch set by moving the logic for TSC to nanosecond
conversion in a separate set.
- Moved the logic for internal refactoring of existing and already merged
time sync logic in a separate set.
v31 changes:
- Removed POC label from the patch introducing the PTP time sync
algorithm.
- Implemented logic for TSC clock to nanoseconds conversion.
- Select x86-tsc clock for the tracing session, is KVM timesync plugin is
available and the user did not specify any trace clock.
v30 changes:
- Moved all time sync logic in the trace-cmd library.
- Separate the logic for pthread barrier time sync threads synchronization
in its own patch.
v29 changes:
- Included <linux/types.h> in trace-timesync-kvm.c for __s64 type.
- Added pthread barrier to host time sync pthread, to ensure times are
synchronized before starting the trace.
- Removed already merged patches from the set.
v28 changes:
- Fix bugs, introduced by previous trace-cmd commits, related to tracefs
library usage.
- Removed unused type defines for trace packets.
v27 changes:
- Fixed broken compilation due to usage of old libtracefs APIs.
- Rewrote complex macros to follow the Linux kernel requirements for macros.
- Removed pathces from the set, that were already merged upstream.
v26 changes:
- Rebased on top of latest master.
- Abstracted Time sync protocol names in a structure, to avoid using
triple char pointers.
- Removed a patch from the set, as it is already merged:
"trace-cmd: Add new libtrasefs API to get the current trace clock".
- Minor coding style changes, for better code readability.
v25 changes:
- Addressed Steven's comments.
- Reorded the patches in the plugin - put the PTP and KVM PoC patches
last and all other fixes and improvements before them.
- Implemented a new libtrasefs API to get the current trace clock.
- Replaced IDs of trace timestamps synchronization protocols with strings.
- Implemented an "accuracy" parameter for timestamps synchronization
protocols.
- Added "scaling ratio" correction, calculated by the timestamp
synchronization protocols.
- Added flags, declared by the timestamps synchronization protocols,
and stored in the trace.dat file, together with the calculated
time offsets.
- Implemented timestamp offset calculation per virtual CPU.
v24 changes:
- trace-cmd internal refactoring, needed for KVM timestamp synchronization
plugin.
- Added KVM timestamp synchronization plugin.
v23 changes:
- Added flags to PTP start message to control the behaviour of the
algorithm. This is for development purposes mostly, to compare and
evaluate how these changes affect the accuracy.
PTP_FLAG_FASTEST_RESPONSE: Consider only the probe with fastest
response time, otherwise make a histogram
from all probes.
PTP_FLAG_USE_MARKER: Use trace marker to get the clock,
otherwise use directly the system clock
v22 changes, addressed Steven's comments:
- Fixed error flow in read_qemu_guests_pids(), free allocated resources
in case of an error.
- Fixed initialisation of reallocated memmory in set_vcpu_pid_mapping().
- Fixed bitmask logic in tracecmd_tsync_proto_select().
- Fixed usage of wrong structure in make_trace_resp().
v21 changes:
- Rebased on top of latest master.
- Remove these two patches from the set, as they are already merged:
trace-cmd: Add new library API for local CPU count
trace-cmd: Add support for negative time offsets in trace.dat file
- Added more descriptive warning message when fails to extract Time Shift
information from the trace.dat file.
- Added a warning message when fails to obtain vcpu - pid mappings.
- Handle the case with sparse VCPU numbers in VCPU - PID mapping
array.
- Fixed broken recording over FIFOs.
v20 changes:
- Rebased on top of latest master.
- Removed the VCPUS_MAX hardcoded limit, reimplemented the cpu_pid[] array
to be dynamically allocated.
- Added a warning when reading of TRACECMD_OPTION_TIME_SHIFT option
fails, due to unexpected option's size.
- Improved loading of TRACECMD_OPTION_GUEST option data, as Steven
suggested.
v19 changes:
- Rebased on top of latest master. The librtacefs is already merged,
this allows to drop few patches from the set and use librtacefs APIs
instead.
- Reimplemented all new trace.dat options to be in binary format,
instead of text. Leverage the new "trace-cmd dump" sub command to
track what is written in the file.
- Addressed Steven's comments.
v18 changes: addressed Steven Rostdet comments:
- Replaced semaphores with pthread mutexes.
- Made bitmask with time sync protocols unlimited, so we can support
more than 32 protocols. That required to redesign the trace request
packet format.
- A lot of small fixes.
v17 changes:
- Implemented new PTP logic for calculating the clocks offset, using
histogram of all PTP samples. It gives better results than the logic
with the fastest response time, so set the new one as default in the
POC patch.
v16 changes:
- Fixed compilation in case no VSOCK is available (Thanks to Slavomir Kaslev)
- Fixed a typo in trace-cmd-record.1.txt (Thanks to Slavomir Kaslev)
- Added forgotten file in the patch "trace-cmd: Add new library APIs for
ftrace instances." - trace-instance.c
- Fixed few compilation warnings related to TSYNC_DEBUG code.
- Removed a blank line at the end of "tsync_readme" file.
v15 changes:
- Removed the patch for "--proc-map" from the series, as it should not
be part of it.
v14 changes:
- Bring back the PTP-like algorithm and removed the ftrace event based logic.
- Reimplemented the PTP-like algorithm to use raw ftrace markers, instead of clock_gettime() API.
- Refactored the logic to be algorithm independent and plugin friendly.
- Implemented continuous timestamps synchronization, while the trace is running.
- Moved logic from trace-cmd application to libtracecmd, as new library APIs.
- Implemented new trace id functionality.
- Implemented new guest section in host trace.dat file.
v13 changes:
- Remove few patches from the set, as they were merged.
- Rebased to the latest master, Slavomirs patchest "Add VM kernel tracing over
vsockets and FIFOs" got merged!
v12 changes:
- Rebased on top of Slavomir's v13 "Add VM kernel tracing over vsockets and FIFOs"
v11 changes:
- Rebased on top of Slavomir's v10 "Add VM kernel tracing over vsockets and FIFOs"
- Addressed Slavomir's commnents from version 10 of the patch series.
v10 changes:
- Fixed broken compilation, call to timestamp_correction_calc() in timestamp_correct
was smashed.
- Replaced deprecated tep_data_event_from_type() API with tep_find_event().
- Fixed a warning on assignment const to non const.
v9 changes:
- Fixed implementation of binary search algorithm in timestamp_correct()
v8 changes:
- Added rmdir() call in tracecmd_remove_instance(), to completely remove the instance.
However, there is an issue with deleting the instances using rmdir(), which is investigated.
- Few changes in read_qemu_guests_pids(), timestamp_correct(), tsync_offset_load()
tracecmd_clock_context_new() and find_raw_events() suggested by Slavomir.
v7 changes:
- Added warning messages in case time synchronization cannot be negotiated or fails.
- Few optimizations and checks in read_qemu_guests_pids(), tsync_offset_load(),
and find_raw_events(), suggested by Slavomir Kaslev.
- Reworked timestamp_correct() to not use static variables.
- Check TRACECMD_OPTION_TIME_SHIFT before reading time sync samples from the trace.dat file
v6 changes:
- Refactored tracecmd_msg_snd_time_sync() and tracecmd_msg_rcv_time_sync() functions:
removed any time sync calculations logic as separate functions in trace-timesync.c file
- Defined TSYNC_PROBE, TSYNC_REQ and TSYNC_RESP messages, in order to make the time sync
protocol comprehensible.
- Addressed Steven Rostedt comments.
- Addressed Slavomir Kaslev commnets.
v5 changes:
- Rebased to Slavomir's v8 "Add VM kernel tracing over vsockets and FIFOs"
patch series.
- Implemented an algorithm for time drift correction.
- Addressed Slavomir's commnets.
- Refactored the code: moved all time sync specific implementation in trace-timesync.c
- Isolated all hardcoded event specific stuff in a structure, so it could be easily
moved to external plugins.
- Added a check for VSOCK support: do not perform vsock dependent time synchronisation
in case there is no VSOCK support.
v4 changes:
- Removed the implementation of PTP-like algorithm. The current
logic relies on matching time stamps of kvm_exit/virtio_transport_recv_pkt
events on host to virtio_transport_alloc_pkt/vp_notify events on guest.
- Rebased to Slavomir's v7 "Add VM kernel tracing over vsockets and FIFOs"
patch series.
- Decreased the time synch probes from 5000 to 300.
- Addressed Steven Rostedt comments.
- Code cleanup.
v3 changes:
- Removed any magic constants, used in the PTP-like algorithm,
as Slavomir Kaslev suggested.
- Implemented new algorithm, based on mapping kvm_exit events
in host context to vsock_send events in guest context,
suggested by Steven Rostedt.
v2 changes:
- Addressed Steven Rostedt comments.
- Modified PTP-like timestamps sync algorithm to gain more accuracy, with the
help of Yordan Karadzhov and Slavomir Kaslev.
Tzvetomir Stoyanov (VMware) (5):
trace-cmd: Add dummy function to initialize timestamp sync logic
trace-cmd: Add timestamp synchronization per vCPU
trace-cmd: PTP-like algorithm for host - guest timestamp
synchronization
trace-cmd: Debug scripts for PTP-like algorithm for host - guest
timestamp synchronization
trace-cmd [POC]: Add KVM timestamp synchronization plugin
lib/trace-cmd/Makefile | 4 +
.../include/private/trace-cmd-private.h | 2 +-
lib/trace-cmd/include/trace-tsync-local.h | 23 +-
lib/trace-cmd/trace-input.c | 175 +++--
lib/trace-cmd/trace-timesync-kvm.c | 533 +++++++++++++
lib/trace-cmd/trace-timesync-ptp.c | 715 ++++++++++++++++++
lib/trace-cmd/trace-timesync.c | 292 +++++--
scripts/debug/tsync_hist.py | 57 ++
scripts/debug/tsync_readme | 12 +
scripts/debug/tsync_res.py | 46 ++
tracecmd/trace-agent.c | 1 +
tracecmd/trace-dump.c | 52 +-
tracecmd/trace-record.c | 25 +-
13 files changed, 1757 insertions(+), 180 deletions(-)
create mode 100644 lib/trace-cmd/trace-timesync-kvm.c
create mode 100644 lib/trace-cmd/trace-timesync-ptp.c
create mode 100644 scripts/debug/tsync_hist.py
create mode 100644 scripts/debug/tsync_readme
create mode 100644 scripts/debug/tsync_res.py
--
2.30.2
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v33 1/5] trace-cmd: Add dummy function to initialize timestamp sync logic
2021-03-25 7:14 [PATCH v33 0/5] Timestamp synchronization of host - guest tracing session Tzvetomir Stoyanov (VMware)
@ 2021-03-25 7:14 ` Tzvetomir Stoyanov (VMware)
2021-03-25 7:14 ` [PATCH v33 2/5] trace-cmd: Add timestamp synchronization per vCPU Tzvetomir Stoyanov (VMware)
` (3 subsequent siblings)
4 siblings, 0 replies; 7+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2021-03-25 7:14 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel, stefano.devenuto99
A dummy empty function is added, will be used to initialize timestamp
synchronization logic:
tracecmd_tsync_init()
When this code is implemented as real plugins, this function will be
removed. Then the initializion will be triggered at plugin load time.
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
lib/trace-cmd/trace-timesync.c | 8 ++++++++
tracecmd/trace-agent.c | 1 +
tracecmd/trace-record.c | 25 ++++++++++++++++---------
3 files changed, 25 insertions(+), 9 deletions(-)
diff --git a/lib/trace-cmd/trace-timesync.c b/lib/trace-cmd/trace-timesync.c
index 0097ce15..62f5dc1e 100644
--- a/lib/trace-cmd/trace-timesync.c
+++ b/lib/trace-cmd/trace-timesync.c
@@ -55,6 +55,14 @@ static struct tsync_proto *tsync_proto_find(const char *proto_name)
return NULL;
}
+/**
+ * tracecmd_tsync_init - Initialize the global, per task, time sync data.
+ */
+void tracecmd_tsync_init(void)
+{
+
+}
+
int tracecmd_tsync_proto_register(const char *proto_name, int accuracy, int roles,
int supported_clocks, unsigned int flags,
int (*init)(struct tracecmd_time_sync *),
diff --git a/tracecmd/trace-agent.c b/tracecmd/trace-agent.c
index 49f6dd8c..1f7d9461 100644
--- a/tracecmd/trace-agent.c
+++ b/tracecmd/trace-agent.c
@@ -250,6 +250,7 @@ static void agent_serve(unsigned int port)
sd = trace_make_vsock(port);
if (sd < 0)
die("Failed to open vsocket");
+ tracecmd_tsync_init();
if (!get_local_cid(&cid))
printf("listening on @%u:%u\n", cid, port);
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 946bcb4d..6e579c22 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -6541,10 +6541,6 @@ out:
free(clock);
}
-/*
- * This function contains common code for the following commands:
- * record, start, stream, profile.
- */
static void record_trace(int argc, char **argv,
struct common_record_context *ctx)
{
@@ -6708,12 +6704,23 @@ static void record_trace(int argc, char **argv,
finalize_record_trace(ctx);
}
+/*
+ * This function contains common code for the following commands:
+ * record, start, stream, profile.
+ */
+static void record_trace_command(int argc, char **argv,
+ struct common_record_context *ctx)
+{
+ tracecmd_tsync_init();
+ record_trace(argc, argv, ctx);
+}
+
void trace_start(int argc, char **argv)
{
struct common_record_context ctx;
parse_record_options(argc, argv, CMD_start, &ctx);
- record_trace(argc, argv, &ctx);
+ record_trace_command(argc, argv, &ctx);
exit(0);
}
@@ -6722,7 +6729,7 @@ void trace_set(int argc, char **argv)
struct common_record_context ctx;
parse_record_options(argc, argv, CMD_set, &ctx);
- record_trace(argc, argv, &ctx);
+ record_trace_command(argc, argv, &ctx);
exit(0);
}
@@ -6805,7 +6812,7 @@ void trace_stream(int argc, char **argv)
struct common_record_context ctx;
parse_record_options(argc, argv, CMD_stream, &ctx);
- record_trace(argc, argv, &ctx);
+ record_trace_command(argc, argv, &ctx);
exit(0);
}
@@ -6824,7 +6831,7 @@ void trace_profile(int argc, char **argv)
if (!buffer_instances)
top_instance.flags |= BUFFER_FL_PROFILE;
- record_trace(argc, argv, &ctx);
+ record_trace_command(argc, argv, &ctx);
do_trace_profile();
exit(0);
}
@@ -6834,7 +6841,7 @@ void trace_record(int argc, char **argv)
struct common_record_context ctx;
parse_record_options(argc, argv, CMD_record, &ctx);
- record_trace(argc, argv, &ctx);
+ record_trace_command(argc, argv, &ctx);
exit(0);
}
--
2.30.2
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v33 2/5] trace-cmd: Add timestamp synchronization per vCPU
2021-03-25 7:14 [PATCH v33 0/5] Timestamp synchronization of host - guest tracing session Tzvetomir Stoyanov (VMware)
2021-03-25 7:14 ` [PATCH v33 1/5] trace-cmd: Add dummy function to initialize timestamp sync logic Tzvetomir Stoyanov (VMware)
@ 2021-03-25 7:14 ` Tzvetomir Stoyanov (VMware)
2021-03-25 7:14 ` [PATCH v33 3/5] trace-cmd: PTP-like algorithm for host - guest timestamp synchronization Tzvetomir Stoyanov (VMware)
` (2 subsequent siblings)
4 siblings, 0 replies; 7+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2021-03-25 7:14 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel, stefano.devenuto99
Timestamp synchronization logic is changed to work per virtual CPU. Some
hypervisors maintain time offset and scaling per vCPU. The host-guest
communication protocol is changed to request time stamp offset calculation
for particular vCPU. The guest thread, responsible for running that logic
is pinned to the requested CPU. The time sync medata data, saved in the
trace.dat file is changed to an array of vCPUs. When an event time stamp
is corrected, the CPU on that the event happened is used to get the
correct offset.
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
.../include/private/trace-cmd-private.h | 2 +-
lib/trace-cmd/include/trace-tsync-local.h | 22 +-
lib/trace-cmd/trace-input.c | 175 +++++++----
lib/trace-cmd/trace-timesync.c | 281 +++++++++++++-----
tracecmd/trace-dump.c | 52 ++--
5 files changed, 361 insertions(+), 171 deletions(-)
diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index fdca7494..899b3fef 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -455,7 +455,7 @@ tracecmd_tsync_with_guest(unsigned long long trace_id, int loop_interval,
unsigned int cid, unsigned int port, int guest_pid,
int guest_cpus, const char *proto_name, const char *clock);
int tracecmd_tsync_with_guest_stop(struct tracecmd_time_sync *tsync);
-int tracecmd_tsync_get_offsets(struct tracecmd_time_sync *tsync,
+int tracecmd_tsync_get_offsets(struct tracecmd_time_sync *tsync, int cpu,
int *count, long long **ts,
long long **offsets, long long **scalings);
int tracecmd_tsync_get_session_params(struct tracecmd_time_sync *tsync,
diff --git a/lib/trace-cmd/include/trace-tsync-local.h b/lib/trace-cmd/include/trace-tsync-local.h
index 5cf4f843..b3a3bdfc 100644
--- a/lib/trace-cmd/include/trace-tsync-local.h
+++ b/lib/trace-cmd/include/trace-tsync-local.h
@@ -24,12 +24,7 @@ struct tracecmd_time_sync {
int vcpu_count;
};
-struct clock_sync_context {
- void *proto_data; /* time sync protocol specific data */
- bool is_server; /* server side time sync role */
- bool is_guest; /* guest or host time sync role */
- struct tracefs_instance *instance; /* ftrace buffer, used for time sync events */
-
+struct clock_sync_offsets {
/* Arrays with calculated time offsets at given time */
int sync_size; /* Allocated size of sync_ts,
* sync_offsets and sync_scalings
@@ -40,6 +35,18 @@ struct clock_sync_context {
long long *sync_ts;
long long *sync_offsets;
long long *sync_scalings;
+};
+
+struct clock_sync_context {
+ void *proto_data; /* time sync protocol specific data */
+ bool is_server; /* server side time sync role */
+ bool is_guest; /* guest or host time sync role */
+ struct tracefs_instance *instance; /* ftrace buffer, used for time sync events */
+
+ int cpu_count;
+ struct clock_sync_offsets *offsets; /* Array of size cpu_count
+ * calculated offsets per CPU
+ */
/* Identifiers of local and remote time sync peers: cid and port */
unsigned int local_cid;
@@ -53,7 +60,8 @@ int tracecmd_tsync_proto_register(const char *proto_name, int accuracy, int role
int (*init)(struct tracecmd_time_sync *),
int (*free)(struct tracecmd_time_sync *),
int (*calc)(struct tracecmd_time_sync *,
- long long *, long long *, long long *));
+ long long *, long long *,
+ long long *, unsigned int));
int tracecmd_tsync_proto_unregister(char *proto_name);
int ptp_clock_sync_register(void);
diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index c0b47345..2f7ba5db 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -91,12 +91,19 @@ struct guest_trace_info {
int *cpu_pid;
};
+struct timesync_offsets {
+ int ts_samples_count;
+ struct ts_offset_sample *ts_samples;
+};
+
struct host_trace_info {
unsigned long long peer_trace_id;
unsigned int flags;
bool sync_enable;
int ts_samples_count;
struct ts_offset_sample *ts_samples;
+ int cpu_count;
+ struct timesync_offsets *ts_offsets;
};
struct tsc2nsec {
@@ -1241,50 +1248,54 @@ timestamp_correction_calc(unsigned long long ts, unsigned int flags,
return ts + tscor;
}
-static unsigned long long timestamp_host_sync(unsigned long long ts,
+static unsigned long long timestamp_host_sync(unsigned long long ts, int cpu,
struct tracecmd_input *handle)
{
- struct host_trace_info *host = &handle->host;
+ struct timesync_offsets *tsync;
int min, mid, max;
+ if (cpu >= handle->host.cpu_count)
+ return ts;
+ tsync = &handle->host.ts_offsets[cpu];
+
/* We have one sample, nothing to calc here */
- if (host->ts_samples_count == 1)
- return ts + host->ts_samples[0].offset;
+ if (tsync->ts_samples_count == 1)
+ return ts + tsync->ts_samples[0].offset;
/* We have two samples, nothing to search here */
- if (host->ts_samples_count == 2)
- return timestamp_correction_calc(ts, host->flags,
- &host->ts_samples[0],
- &host->ts_samples[1]);
+ if (tsync->ts_samples_count == 2)
+ return timestamp_correction_calc(ts, handle->host.flags,
+ &tsync->ts_samples[0],
+ &tsync->ts_samples[1]);
/* We have more than two samples */
- if (ts <= host->ts_samples[0].time)
- return timestamp_correction_calc(ts, host->flags,
- &host->ts_samples[0],
- &host->ts_samples[1]);
- else if (ts >= host->ts_samples[host->ts_samples_count-1].time)
- return timestamp_correction_calc(ts, host->flags,
- &host->ts_samples[host->ts_samples_count-2],
- &host->ts_samples[host->ts_samples_count-1]);
+ if (ts <= tsync->ts_samples[0].time)
+ return timestamp_correction_calc(ts, handle->host.flags,
+ &tsync->ts_samples[0],
+ &tsync->ts_samples[1]);
+ else if (ts >= tsync->ts_samples[tsync->ts_samples_count-1].time)
+ return timestamp_correction_calc(ts, handle->host.flags,
+ &tsync->ts_samples[tsync->ts_samples_count-2],
+ &tsync->ts_samples[tsync->ts_samples_count-1]);
min = 0;
- max = host->ts_samples_count-1;
+ max = tsync->ts_samples_count-1;
mid = (min + max)/2;
while (min <= max) {
- if (ts < host->ts_samples[mid].time)
+ if (ts < tsync->ts_samples[mid].time)
max = mid - 1;
- else if (ts > host->ts_samples[mid].time)
+ else if (ts > tsync->ts_samples[mid].time)
min = mid + 1;
else
break;
mid = (min + max)/2;
}
- return timestamp_correction_calc(ts, host->flags,
- &host->ts_samples[mid],
- &host->ts_samples[mid+1]);
+ return timestamp_correction_calc(ts, handle->host.flags,
+ &tsync->ts_samples[mid],
+ &tsync->ts_samples[mid+1]);
}
-static unsigned long long timestamp_calc(unsigned long long ts,
+static unsigned long long timestamp_calc(unsigned long long ts, int cpu,
struct tracecmd_input *handle)
{
/* do not modify raw timestamps */
@@ -1293,7 +1304,7 @@ static unsigned long long timestamp_calc(unsigned long long ts,
/* Guest trace file, sync with host timestamps */
if (handle->host.sync_enable)
- ts = timestamp_host_sync(ts, handle);
+ ts = timestamp_host_sync(ts, cpu, handle);
if (handle->ts2secs) {
/* user specified clock frequency */
@@ -1333,7 +1344,7 @@ static int update_page_info(struct tracecmd_input *handle, int cpu)
return -1;
}
handle->cpu_data[cpu].timestamp = timestamp_calc(kbuffer_timestamp(kbuf),
- handle);
+ cpu, handle);
return 0;
}
@@ -1963,7 +1974,7 @@ read_again:
goto read_again;
}
- handle->cpu_data[cpu].timestamp = timestamp_calc(ts, handle);
+ handle->cpu_data[cpu].timestamp = timestamp_calc(ts, cpu, handle);
index = kbuffer_curr_offset(kbuf);
@@ -2293,34 +2304,79 @@ static int tsync_offset_cmp(const void *a, const void *b)
return 0;
}
-static void tsync_offset_load(struct tracecmd_input *handle, char *buf)
+#define safe_read(R, C) \
+ do { \
+ if ((C) > size) \
+ return -EFAULT; \
+ (R) = tep_read_number(tep, buf, (C)); \
+ buf += (C); \
+ size -= (C); \
+ } while (0)
+
+#define safe_read_loop(type) \
+ do { \
+ int i; \
+ for (i = 0; i < ts_offsets->ts_samples_count; i++) \
+ safe_read(ts_offsets->ts_samples[i].type, 8); \
+ } while (0)
+
+static int tsync_offset_load(struct tep_handle *tep,
+ struct timesync_offsets *ts_offsets, char *buf, int size)
{
- struct host_trace_info *host = &handle->host;
- long long *buf8 = (long long *)buf;
+ int start_size = size;
int i, j;
- for (i = 0; i < host->ts_samples_count; i++) {
- host->ts_samples[i].time = tep_read_number(handle->pevent,
- buf8 + i, 8);
- host->ts_samples[i].offset = tep_read_number(handle->pevent,
- buf8 + host->ts_samples_count + i, 8);
- host->ts_samples[i].scaling = tep_read_number(handle->pevent,
- buf8 + (2 * host->ts_samples_count) + i, 8);
- }
- qsort(host->ts_samples, host->ts_samples_count,
+ safe_read_loop(time);
+ safe_read_loop(offset);
+ safe_read_loop(scaling);
+ qsort(ts_offsets->ts_samples, ts_offsets->ts_samples_count,
sizeof(struct ts_offset_sample), tsync_offset_cmp);
/* Filter possible samples with equal time */
- for (i = 0, j = 0; i < host->ts_samples_count; i++) {
- if (i == 0 || host->ts_samples[i].time != host->ts_samples[i-1].time)
- host->ts_samples[j++] = host->ts_samples[i];
+ for (i = 0, j = 0; i < ts_offsets->ts_samples_count; i++) {
+ if (i == 0 || ts_offsets->ts_samples[i].time != ts_offsets->ts_samples[i-1].time)
+ ts_offsets->ts_samples[j++] = ts_offsets->ts_samples[i];
}
- host->ts_samples_count = j;
+ ts_offsets->ts_samples_count = j;
+
+ return start_size - size;
+}
+
+static int tsync_cpu_offsets_load(struct tracecmd_input *handle, char *buf, int size)
+{
+ struct tep_handle *tep = handle->pevent;
+ int ret;
+ int i;
+
+ safe_read(handle->host.cpu_count, 4);
+ handle->host.ts_offsets = calloc(handle->host.cpu_count,
+ sizeof(struct timesync_offsets));
+ if (!handle->host.ts_offsets)
+ return -ENOMEM;
+ for (i = 0; i < handle->host.cpu_count; i++) {
+ safe_read(handle->host.ts_offsets[i].ts_samples_count, 4);
+ handle->host.ts_offsets[i].ts_samples = calloc(handle->host.ts_offsets[i].ts_samples_count,
+ sizeof(struct ts_offset_sample));
+ if (!handle->host.ts_offsets[i].ts_samples)
+ return -ENOMEM;
+ ret = tsync_offset_load(tep, &handle->host.ts_offsets[i], buf, size);
+ if (ret <= 0)
+ return -EFAULT;
+ size -= ret;
+ buf += ret;
+ }
+ return 0;
}
static void trace_tsync_offset_free(struct host_trace_info *host)
{
- free(host->ts_samples);
- host->ts_samples = NULL;
+ int i;
+
+ if (host->ts_offsets) {
+ for (i = 0; i < host->cpu_count; i++)
+ free(host->ts_offsets[i].ts_samples);
+ free(host->ts_offsets);
+ host->ts_offsets = NULL;
+ }
}
static int trace_pid_map_cmp(const void *a, const void *b)
@@ -2574,8 +2630,8 @@ static int handle_options(struct tracecmd_input *handle)
struct input_buffer_instance *buffer;
struct hook_list *hook;
char *buf;
- int samples_size;
int cpus;
+ int ret;
/* By default, use usecs, unless told otherwise */
handle->flags |= TRACECMD_FL_IN_USECS;
@@ -2627,11 +2683,15 @@ static int handle_options(struct tracecmd_input *handle)
/*
* long long int (8 bytes) trace session ID
* int (4 bytes) protocol flags.
- * int (4 bytes) count of timestamp offsets.
- * long long array of size [count] of times,
+ * int (4 bytes) CPU count.
+ * array of size [CPU count]:
+ * [
+ * int (4 bytes) count of timestamp offsets.
+ * long long array of size [count] of times,
* when the offsets were calculated.
- * long long array of size [count] of timestamp offsets.
- * long long array of size [count] of timestamp scaling ratios.*
+ * long long array of size [count] of timestamp offsets.
+ * long long array of size [count] of timestamp scaling ratios.*
+ * ]
*/
if (size < 16 || (handle->flags & TRACECMD_FL_RAW_TS))
break;
@@ -2639,18 +2699,9 @@ static int handle_options(struct tracecmd_input *handle)
buf, 8);
handle->host.flags = tep_read_number(handle->pevent,
buf + 8, 4);
- handle->host.ts_samples_count = tep_read_number(handle->pevent,
- buf + 12, 4);
- samples_size = (8 * handle->host.ts_samples_count);
- if (size != (16 + (2 * samples_size))) {
- warning("Failed to extract Time Shift information from the file: found size %d, expected is %d",
- size, 16 + (2 * samples_size));
- break;
- }
- handle->host.ts_samples = malloc(2 * samples_size);
- if (!handle->host.ts_samples)
- return -ENOMEM;
- tsync_offset_load(handle, buf + 16);
+ ret = tsync_cpu_offsets_load(handle, buf + 12, size - 12);
+ if (ret < 0)
+ return ret;
tracecmd_enable_tsync(handle, true);
break;
case TRACECMD_OPTION_CPUSTAT:
@@ -4057,7 +4108,7 @@ int tracecmd_get_guest_cpumap(struct tracecmd_input *handle,
int tracecmd_enable_tsync(struct tracecmd_input *handle, bool enable)
{
if (enable &&
- (!handle->host.ts_samples || !handle->host.ts_samples_count))
+ (!handle->host.ts_offsets || !handle->host.cpu_count))
return -1;
handle->host.sync_enable = enable;
diff --git a/lib/trace-cmd/trace-timesync.c b/lib/trace-cmd/trace-timesync.c
index 62f5dc1e..556004f1 100644
--- a/lib/trace-cmd/trace-timesync.c
+++ b/lib/trace-cmd/trace-timesync.c
@@ -36,9 +36,13 @@ struct tsync_proto {
int (*clock_sync_free)(struct tracecmd_time_sync *clock_context);
int (*clock_sync_calc)(struct tracecmd_time_sync *clock_context,
long long *offset, long long *scaling,
- long long *timestamp);
+ long long *timestamp, unsigned int cpu);
};
+struct tsync_probe_request_msg {
+ unsigned short cpu;
+} __packed;
+
static struct tsync_proto *tsync_proto_list;
static struct tsync_proto *tsync_proto_find(const char *proto_name)
@@ -68,7 +72,8 @@ int tracecmd_tsync_proto_register(const char *proto_name, int accuracy, int role
int (*init)(struct tracecmd_time_sync *),
int (*free)(struct tracecmd_time_sync *),
int (*calc)(struct tracecmd_time_sync *,
- long long *, long long *, long long *))
+ long long *, long long *,
+ long long *, unsigned int))
{
struct tsync_proto *proto = NULL;
@@ -80,6 +85,7 @@ int tracecmd_tsync_proto_register(const char *proto_name, int accuracy, int role
strncpy(proto->proto_name, proto_name, TRACECMD_TSYNC_PNAME_LENGTH);
proto->accuracy = accuracy;
proto->roles = roles;
+ proto->flags = flags;
proto->supported_clocks = supported_clocks;
proto->clock_sync_init = init;
proto->clock_sync_free = free;
@@ -122,6 +128,7 @@ bool tsync_proto_is_supported(const char *proto_name)
* tracecmd_tsync_get_offsets - Return the calculated time offsets
*
* @tsync: Pointer to time sync context
+ * @cpu: CPU for which to get the calculated offsets
* @count: Returns the number of calculated time offsets
* @ts: Array of size @count containing timestamps of callculated offsets
* @offsets: array of size @count, containing offsets for each timestamp
@@ -129,23 +136,25 @@ bool tsync_proto_is_supported(const char *proto_name)
*
* Retuns -1 in case of an error, or 0 otherwise
*/
-int tracecmd_tsync_get_offsets(struct tracecmd_time_sync *tsync,
- int *count, long long **ts,
- long long **offsets, long long **scalings)
+int tracecmd_tsync_get_offsets(struct tracecmd_time_sync *tsync, int cpu,
+ int *count, long long **ts,
+ long long **offsets, long long **scalings)
{
struct clock_sync_context *tsync_context;
if (!tsync || !tsync->context)
return -1;
tsync_context = (struct clock_sync_context *)tsync->context;
+ if (cpu >= tsync_context->cpu_count || !tsync_context->offsets)
+ return -1;
if (count)
- *count = tsync_context->sync_count;
+ *count = tsync_context->offsets[cpu].sync_count;
if (ts)
- *ts = tsync_context->sync_ts;
+ *ts = tsync_context->offsets[cpu].sync_ts;
if (offsets)
- *offsets = tsync_context->sync_offsets;
+ *offsets = tsync_context->offsets[cpu].sync_offsets;
if (scalings)
- *scalings = tsync_context->sync_scalings;
+ *scalings = tsync_context->offsets[cpu].sync_scalings;
return 0;
}
@@ -496,6 +505,13 @@ static int clock_context_init(struct tracecmd_time_sync *tsync,
if (!clock->instance)
goto error;
+ clock->cpu_count = tsync->vcpu_count;
+ if (clock->cpu_count) {
+ clock->offsets = calloc(clock->cpu_count, sizeof(struct clock_sync_offsets));
+ if (!clock->offsets)
+ goto error;
+ }
+
tsync->context = clock;
if (protocol->clock_sync_init && protocol->clock_sync_init(tsync) < 0)
goto error;
@@ -505,6 +521,9 @@ static int clock_context_init(struct tracecmd_time_sync *tsync,
return 0;
error:
tsync->context = NULL;
+ if (clock->instance)
+ clock_synch_delete_instance(clock->instance);
+ free(clock->offsets);
free(clock);
return -1;
}
@@ -520,6 +539,7 @@ void tracecmd_tsync_free(struct tracecmd_time_sync *tsync)
{
struct clock_sync_context *tsync_context;
struct tsync_proto *proto;
+ int i;
if (!tsync->context)
return;
@@ -532,14 +552,20 @@ void tracecmd_tsync_free(struct tracecmd_time_sync *tsync)
clock_synch_delete_instance(tsync_context->instance);
tsync_context->instance = NULL;
- free(tsync_context->sync_ts);
- free(tsync_context->sync_offsets);
- free(tsync_context->sync_scalings);
- tsync_context->sync_ts = NULL;
- tsync_context->sync_offsets = NULL;
- tsync_context->sync_scalings = NULL;
- tsync_context->sync_count = 0;
- tsync_context->sync_size = 0;
+ if (tsync_context->cpu_count && tsync_context->offsets) {
+ for (i = 0; i < tsync_context->cpu_count; i++) {
+ free(tsync_context->offsets[i].sync_ts);
+ free(tsync_context->offsets[i].sync_offsets);
+ free(tsync_context->offsets[i].sync_scalings);
+ tsync_context->offsets[i].sync_ts = NULL;
+ tsync_context->offsets[i].sync_offsets = NULL;
+ tsync_context->offsets[i].sync_scalings = NULL;
+ tsync_context->offsets[i].sync_count = 0;
+ tsync_context->offsets[i].sync_size = 0;
+ }
+ free(tsync_context->offsets);
+ tsync_context->offsets = NULL;
+ }
pthread_mutex_destroy(&tsync->lock);
pthread_cond_destroy(&tsync->cond);
pthread_barrier_destroy(&tsync->first_sync);
@@ -548,15 +574,69 @@ void tracecmd_tsync_free(struct tracecmd_time_sync *tsync)
free(tsync);
}
+static cpu_set_t *pin_to_cpu(int cpu)
+{
+ static size_t size;
+ static int cpus;
+ cpu_set_t *mask = NULL;
+ cpu_set_t *old = NULL;
+
+ if (!cpus) {
+ cpus = tracecmd_count_cpus();
+ size = CPU_ALLOC_SIZE(cpus);
+ }
+ if (cpu >= cpus)
+ goto error;
+
+ mask = CPU_ALLOC(cpus);
+ if (!mask)
+ goto error;
+ old = CPU_ALLOC(cpus);
+ if (!old)
+ goto error;
+
+ CPU_ZERO_S(size, mask);
+ CPU_SET_S(cpu, size, mask);
+ if (pthread_getaffinity_np(pthread_self(), size, old))
+ goto error;
+ if (pthread_setaffinity_np(pthread_self(), size, mask))
+ goto error;
+
+ CPU_FREE(mask);
+ return old;
+
+error:
+ if (mask)
+ CPU_FREE(mask);
+ if (old)
+ CPU_FREE(old);
+ return NULL;
+}
+
+static void restore_pin_to_cpu(cpu_set_t *mask)
+{
+ static size_t size;
+
+ if (!size)
+ size = CPU_ALLOC_SIZE(tracecmd_count_cpus());
+
+ pthread_setaffinity_np(pthread_self(), size, mask);
+ CPU_FREE(mask);
+}
+
static int tsync_send(struct tracecmd_time_sync *tsync,
- struct tsync_proto *proto)
+ struct tsync_proto *proto, unsigned int cpu)
{
+ cpu_set_t *old_set = NULL;
long long timestamp = 0;
long long scaling = 0;
long long offset = 0;
int ret;
- ret = proto->clock_sync_calc(tsync, &offset, &scaling, ×tamp);
+ old_set = pin_to_cpu(cpu);
+ ret = proto->clock_sync_calc(tsync, &offset, &scaling, ×tamp, cpu);
+ if (old_set)
+ restore_pin_to_cpu(old_set);
return ret;
}
@@ -564,55 +644,48 @@ static int tsync_send(struct tracecmd_time_sync *tsync,
static void tsync_with_host(struct tracecmd_time_sync *tsync)
{
char protocol[TRACECMD_TSYNC_PNAME_LENGTH];
+ struct tsync_probe_request_msg probe;
struct tsync_proto *proto;
unsigned int command;
+ unsigned int size;
+ char *msg;
int ret;
clock_context_init(tsync, &proto, true);
if (!tsync->context)
return;
+ msg = (char *)&probe;
+ size = sizeof(probe);
while (true) {
+ memset(&probe, 0, size);
ret = tracecmd_msg_recv_time_sync(tsync->msg_handle,
protocol, &command,
- NULL, NULL);
+ &size, &msg);
if (ret || strncmp(protocol, TRACECMD_TSYNC_PROTO_NONE, TRACECMD_TSYNC_PNAME_LENGTH) ||
command != TRACECMD_TIME_SYNC_CMD_PROBE)
break;
- ret = tsync_send(tsync, proto);
+ ret = tsync_send(tsync, proto, probe.cpu);
if (ret)
break;
}
}
-static int tsync_get_sample(struct tracecmd_time_sync *tsync,
- struct tsync_proto *proto, int array_step)
+static int record_sync_sample(struct clock_sync_offsets *offsets, int array_step,
+ long long offset, long long scaling, long long ts)
{
- struct clock_sync_context *clock;
long long *sync_scalings = NULL;
long long *sync_offsets = NULL;
long long *sync_ts = NULL;
- long long timestamp = 0;
- long long scaling = 0;
- long long offset = 0;
- int ret;
- ret = proto->clock_sync_calc(tsync, &offset, &scaling, ×tamp);
- if (ret) {
- warning("Failed to synchronize timestamps with guest");
- return -1;
- }
- if (!offset || !timestamp || !scaling)
- return 0;
- clock = tsync->context;
- if (clock->sync_count >= clock->sync_size) {
- sync_ts = realloc(clock->sync_ts,
- (clock->sync_size + array_step) * sizeof(long long));
- sync_offsets = realloc(clock->sync_offsets,
- (clock->sync_size + array_step) * sizeof(long long));
- sync_scalings = realloc(clock->sync_scalings,
- (clock->sync_size + array_step) * sizeof(long long));
+ if (offsets->sync_count >= offsets->sync_size) {
+ sync_ts = realloc(offsets->sync_ts,
+ (offsets->sync_size + array_step) * sizeof(long long));
+ sync_offsets = realloc(offsets->sync_offsets,
+ (offsets->sync_size + array_step) * sizeof(long long));
+ sync_scalings = realloc(offsets->sync_scalings,
+ (offsets->sync_size + array_step) * sizeof(long long));
if (!sync_ts || !sync_offsets || !sync_scalings) {
free(sync_ts);
@@ -620,20 +693,43 @@ static int tsync_get_sample(struct tracecmd_time_sync *tsync,
free(sync_scalings);
return -1;
}
- clock->sync_size += array_step;
- clock->sync_ts = sync_ts;
- clock->sync_offsets = sync_offsets;
- clock->sync_scalings = sync_scalings;
+ offsets->sync_size += array_step;
+ offsets->sync_ts = sync_ts;
+ offsets->sync_offsets = sync_offsets;
+ offsets->sync_scalings = sync_scalings;
}
- clock->sync_ts[clock->sync_count] = timestamp;
- clock->sync_offsets[clock->sync_count] = offset;
- clock->sync_scalings[clock->sync_count] = scaling;
- clock->sync_count++;
+ offsets->sync_ts[offsets->sync_count] = ts;
+ offsets->sync_offsets[offsets->sync_count] = offset;
+ offsets->sync_scalings[offsets->sync_count] = scaling;
+ offsets->sync_count++;
return 0;
}
+static int tsync_get_sample(struct tracecmd_time_sync *tsync, unsigned int cpu,
+ struct tsync_proto *proto, int array_step)
+{
+ struct clock_sync_context *clock;
+ long long timestamp = 0;
+ long long scaling = 0;
+ long long offset = 0;
+ int ret;
+
+ ret = proto->clock_sync_calc(tsync, &offset, &scaling, ×tamp, cpu);
+ if (ret) {
+ warning("Failed to synchronize timestamps with guest");
+ return -1;
+ }
+ if (!offset || !timestamp || !scaling)
+ return 0;
+ clock = tsync->context;
+ if (!clock || cpu >= clock->cpu_count || !clock->offsets)
+ return -1;
+ return record_sync_sample(&clock->offsets[cpu], array_step,
+ offset, scaling, timestamp);
+}
+
#define TIMER_SEC_NANO 1000000000LL
static inline void get_ts_loop_delay(struct timespec *timeout, int delay_ms)
{
@@ -651,12 +747,14 @@ static inline void get_ts_loop_delay(struct timespec *timeout, int delay_ms)
#define CLOCK_TS_ARRAY 5
static int tsync_with_guest(struct tracecmd_time_sync *tsync)
{
+ struct tsync_probe_request_msg probe;
int ts_array_size = CLOCK_TS_ARRAY;
struct tsync_proto *proto;
struct timespec timeout;
bool first = true;
bool end = false;
int ret;
+ int i;
clock_context_init(tsync, &proto, false);
if (!tsync->context) {
@@ -670,16 +768,21 @@ static int tsync_with_guest(struct tracecmd_time_sync *tsync)
while (true) {
pthread_mutex_lock(&tsync->lock);
- ret = tracecmd_msg_send_time_sync(tsync->msg_handle,
- TRACECMD_TSYNC_PROTO_NONE,
- TRACECMD_TIME_SYNC_CMD_PROBE,
- 0, NULL);
- ret = tsync_get_sample(tsync, proto, ts_array_size);
+ for (i = 0; i < tsync->vcpu_count; i++) {
+ probe.cpu = i;
+ ret = tracecmd_msg_send_time_sync(tsync->msg_handle,
+ TRACECMD_TSYNC_PROTO_NONE,
+ TRACECMD_TIME_SYNC_CMD_PROBE,
+ sizeof(probe), (char *)&probe);
+ ret = tsync_get_sample(tsync, i, proto, ts_array_size);
+ if (ret)
+ break;
+ }
if (first) {
first = false;
pthread_barrier_wait(&tsync->first_sync);
}
- if (ret || end)
+ if (end || i < tsync->vcpu_count)
break;
if (tsync->loop_interval > 0) {
get_ts_loop_delay(&timeout, tsync->loop_interval);
@@ -813,41 +916,63 @@ error:
int tracecmd_write_guest_time_shift(struct tracecmd_output *handle,
struct tracecmd_time_sync *tsync)
{
- struct iovec vector[6];
+ struct iovec *vector = NULL;
unsigned int flags;
long long *scalings = NULL;
long long *offsets = NULL;
long long *ts = NULL;
+ int vcount;
int count;
- int ret;
+ int i, j;
+ int ret = -1;
- ret = tracecmd_tsync_get_offsets(tsync, &count,
- &ts, &offsets, &scalings);
- if (ret < 0 || !count || !ts || !offsets || !scalings)
+ if (!tsync->vcpu_count)
+ return -1;
+ vcount = 3 + (4 * tsync->vcpu_count);
+ vector = calloc(vcount, sizeof(struct iovec));
+ if (!vector)
return -1;
ret = tsync_get_proto_flags(tsync, &flags);
if (ret < 0)
- return -1;
-
- vector[0].iov_len = 8;
- vector[0].iov_base = &(tsync->trace_id);
- vector[1].iov_len = 4;
- vector[1].iov_base = &flags;
- vector[2].iov_len = 4;
- vector[2].iov_base = &count;
- vector[3].iov_len = 8 * count;
- vector[3].iov_base = ts;
- vector[4].iov_len = 8 * count;
- vector[4].iov_base = offsets;
- vector[5].iov_len = 8 * count;
- vector[5].iov_base = scalings;
- tracecmd_add_option_v(handle, TRACECMD_OPTION_TIME_SHIFT, vector, 6);
+ goto out;
+
+ j = 0;
+ vector[j].iov_len = 8;
+ vector[j++].iov_base = &tsync->trace_id;
+ vector[j].iov_len = 4;
+ vector[j++].iov_base = &flags;
+ vector[j].iov_len = 4;
+ vector[j++].iov_base = &tsync->vcpu_count;
+ for (i = 0; i < tsync->vcpu_count; i++) {
+ if (j >= vcount)
+ break;
+ ret = tracecmd_tsync_get_offsets(tsync, i, &count,
+ &ts, &offsets, &scalings);
+ if (ret < 0 || !count || !ts || !offsets || !scalings)
+ break;
+ vector[j].iov_len = 4;
+ vector[j++].iov_base = &count;
+ vector[j].iov_len = 8 * count;
+ vector[j++].iov_base = ts;
+ vector[j].iov_len = 8 * count;
+ vector[j++].iov_base = offsets;
+ vector[j].iov_len = 8 * count;
+ vector[j++].iov_base = scalings;
+ }
+ if (i < tsync->vcpu_count) {
+ ret = -1;
+ goto out;
+ }
+ tracecmd_add_option_v(handle, TRACECMD_OPTION_TIME_SHIFT, vector, vcount);
#ifdef TSYNC_DEBUG
if (count > 1)
printf("Got %d timestamp synch samples in %lld ns trace\n\r",
count, ts[count - 1] - ts[0]);
#endif
- return 0;
+ ret = 0;
+out:
+ free(vector);
+ return ret;
}
/**
diff --git a/tracecmd/trace-dump.c b/tracecmd/trace-dump.c
index b6ae5638..3f56f65a 100644
--- a/tracecmd/trace-dump.c
+++ b/tracecmd/trace-dump.c
@@ -377,7 +377,8 @@ static void dump_option_timeshift(int fd, int size)
long long trace_id;
unsigned int count;
unsigned int flags;
- int i;
+ unsigned int cpus;
+ int i, j;
/*
* long long int (8 bytes) trace session ID
@@ -395,29 +396,34 @@ static void dump_option_timeshift(int fd, int size)
do_print(OPTIONS, "0x%llX [peer's trace id]\n", trace_id);
read_file_number(fd, &flags, 4);
do_print(OPTIONS, "0x%llX [peer's protocol flags]\n", flags);
- read_file_number(fd, &count, 4);
- do_print(OPTIONS, "%lld [samples count]\n", count);
- times = calloc(count, sizeof(long long));
- if (!times)
- goto out;
- offsets = calloc(count, sizeof(long long));
- if (!offsets)
- goto out;
- scalings = calloc(count, sizeof(long long));
- if (!scalings)
- goto out;
-
- for (i = 0; i < count; i++)
- read_file_number(fd, times + i, 8);
- for (i = 0; i < count; i++)
- read_file_number(fd, offsets + i, 8);
- for (i = 0; i < count; i++)
- read_file_number(fd, scalings + i, 8);
-
- for (i = 0; i < count; i++)
- do_print(OPTIONS, "\t%lld * %lld %llu [offset * scaling @ time]\n",
- offsets[i], scalings[1], times[i]);
+ read_file_number(fd, &cpus, 4);
+ do_print(OPTIONS, "0x%llX [peer's CPU count]\n", cpus);
+ for (j = 0; j < cpus; j++) {
+ read_file_number(fd, &count, 4);
+ do_print(OPTIONS, "%lld [samples count for CPU %d]\n", count, j);
+ times = calloc(count, sizeof(long long));
+ offsets = calloc(count, sizeof(long long));
+ scalings = calloc(count, sizeof(long long));
+ if (!times || !offsets || !scalings)
+ goto out;
+ for (i = 0; i < count; i++)
+ read_file_number(fd, times + i, 8);
+ for (i = 0; i < count; i++)
+ read_file_number(fd, offsets + i, 8);
+ for (i = 0; i < count; i++)
+ read_file_number(fd, scalings + i, 8);
+
+ for (i = 0; i < count; i++)
+ do_print(OPTIONS, "\t%lld %lld %llu [offset * scaling @ time]\n",
+ offsets[i], scalings[1], times[i]);
+ free(times);
+ free(offsets);
+ free(scalings);
+ times = NULL;
+ offsets = NULL;
+ scalings = NULL;
+ }
out:
free(times);
free(offsets);
--
2.30.2
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v33 3/5] trace-cmd: PTP-like algorithm for host - guest timestamp synchronization
2021-03-25 7:14 [PATCH v33 0/5] Timestamp synchronization of host - guest tracing session Tzvetomir Stoyanov (VMware)
2021-03-25 7:14 ` [PATCH v33 1/5] trace-cmd: Add dummy function to initialize timestamp sync logic Tzvetomir Stoyanov (VMware)
2021-03-25 7:14 ` [PATCH v33 2/5] trace-cmd: Add timestamp synchronization per vCPU Tzvetomir Stoyanov (VMware)
@ 2021-03-25 7:14 ` Tzvetomir Stoyanov (VMware)
2021-03-25 7:14 ` [PATCH v33 4/5] trace-cmd: Debug scripts for " Tzvetomir Stoyanov (VMware)
2021-03-25 7:14 ` [PATCH v33 5/5] trace-cmd [POC]: Add KVM timestamp synchronization plugin Tzvetomir Stoyanov (VMware)
4 siblings, 0 replies; 7+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2021-03-25 7:14 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel, stefano.devenuto99
PTP protocol is designed for synchronizing clocks of machines in a local network.
The same approach can be used for host - guest timestamp synchronization.
This implementation uses ftrace raw markers to track trace timestamps of PTP events.
The patch is a POC, two different algorithms for PTP calculations are proposed:
- Choosing the sample with the fastest response time for calculating the clocks offset.
- Calculating the clocks offset using the average of all PTP samples.
The implementation can be tuned using those parameters:
- #define FASTEST_RESPONSE - is defined, the sample with the fastest response time
is used for calculating the clocks offset. Otherwise the histogram of all samples is used.
- #define PTP_SYNC_LOOP 340 - defines the number of samples, used for one calculation.
- --tsync-interval - a trace-cmd argument, choose the intervals between offset calculations,
performed continuously during the trace.
- #define TSYNC_DEBUG - if defined, a debug information is collected and stored in files,
in the guest machine:
s-cid*.txt - For each offset calculation: host and guest clocks and calculated offset.
res-cid*.txt - For each tracing session: all calculated clock offsets.
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
lib/trace-cmd/Makefile | 3 +
lib/trace-cmd/trace-timesync-ptp.c | 715 +++++++++++++++++++++++++++++
lib/trace-cmd/trace-timesync.c | 4 +-
3 files changed, 721 insertions(+), 1 deletion(-)
create mode 100644 lib/trace-cmd/trace-timesync-ptp.c
diff --git a/lib/trace-cmd/Makefile b/lib/trace-cmd/Makefile
index aa92c8c0..486ea7d1 100644
--- a/lib/trace-cmd/Makefile
+++ b/lib/trace-cmd/Makefile
@@ -21,6 +21,9 @@ ifeq ($(PERF_DEFINED), 1)
OBJS += trace-perf.o
endif
OBJS += trace-timesync.o
+ifeq ($(VSOCK_DEFINED), 1)
+OBJS += trace-timesync-ptp.o
+endif
# Additional util objects
OBJS += trace-blk-hack.o
diff --git a/lib/trace-cmd/trace-timesync-ptp.c b/lib/trace-cmd/trace-timesync-ptp.c
new file mode 100644
index 00000000..b05f1cd0
--- /dev/null
+++ b/lib/trace-cmd/trace-timesync-ptp.c
@@ -0,0 +1,715 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ * Copyright (C) 2019, VMware, Tzvetomir Stoyanov tz.stoyanov@gmail.com>
+ *
+ */
+
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <linux/vm_sockets.h>
+#include <sys/types.h>
+#include <linux/types.h>
+#include <time.h>
+#include <sched.h>
+#include <limits.h>
+
+#include "trace-cmd.h"
+#include "trace-cmd-private.h"
+#include "tracefs.h"
+#include "trace-tsync-local.h"
+#include "trace-msg.h"
+#include "trace-cmd-local.h"
+
+typedef __be32 be32;
+typedef __u64 u64;
+typedef __s64 s64;
+
+#define PTP_SYNC_LOOP 339
+
+#define PTP_SYNC_PKT_START 1
+#define PTP_SYNC_PKT_PROBE 2
+#define PTP_SYNC_PKT_PROBES 3
+#define PTP_SYNC_PKT_OFFSET 4
+#define PTP_SYNC_PKT_END 5
+
+/* print time sync debug messages */
+#define TSYNC_DEBUG
+
+struct ptp_clock_sync {
+ struct tep_handle *tep;
+ struct tep_format_field *id;
+ int raw_id;
+ int marker_fd;
+ int series_id;
+ int flags;
+ int debug_fd;
+};
+
+enum {
+/*
+ * Consider only the probe with fastest response time,
+ * otherwise make a histogram from all probes.
+ */
+ PTP_FLAG_FASTEST_RESPONSE = (1 << 0),
+/*
+ * Use trace marker to get the clock,
+ * otherwise use the system clock directly.
+ */
+ PTP_FLAG_USE_MARKER = (1 << 1),
+};
+static int ptp_flags = PTP_FLAG_FASTEST_RESPONSE | PTP_FLAG_USE_MARKER;
+
+/*
+ * Calculated using formula [CPU rate]*[calculated offset deviation]
+ * tested on 3GHz CPU, with x86-tsc trace clock and compare the calculated
+ * offset with /sys/kernel/debug/kvm/<VM ID>/vcpu0/tsc-offset
+ * measured 2000ns deviation
+ * using PTP flags PTP_FLAG_FASTEST_RESPONSE | PTP_FLAG_USE_MARKER
+ */
+#define PTP_ACCURACY 6000
+#define PTP_NAME "ptp"
+
+struct ptp_clock_start_msg {
+ be32 series_id;
+ be32 flags;
+} __packed;
+
+struct ptp_clock_sample {
+ s64 ts;
+ be32 id;
+} __packed;
+
+struct ptp_clock_result_msg {
+ be32 series_id;
+ be32 count;
+ struct ptp_clock_sample samples[2*PTP_SYNC_LOOP];
+} __packed;
+
+struct ptp_clock_offset_msg {
+ s64 ts;
+ s64 offset;
+};
+
+struct ptp_markers_context {
+ struct clock_sync_context *clock;
+ struct ptp_clock_sync *ptp;
+ struct ptp_clock_result_msg msg;
+ int size;
+};
+
+struct ptp_marker_buf {
+ int local_cid;
+ int remote_cid;
+ int count;
+ int packet_id;
+} __packed;
+
+struct ptp_marker {
+ int series_id;
+ struct ptp_marker_buf data;
+} __packed;
+
+static int ptp_clock_sync_init(struct tracecmd_time_sync *tsync)
+{
+ const char *systems[] = {"ftrace", NULL};
+ struct clock_sync_context *clock_context;
+ struct ptp_clock_sync *ptp;
+ struct tep_event *raw;
+ char *path;
+
+ if (!tsync || !tsync->context)
+ return -1;
+ clock_context = (struct clock_sync_context *)tsync->context;
+ if (clock_context->proto_data)
+ return 0;
+
+ ptp = calloc(1, sizeof(struct ptp_clock_sync));
+ if (!ptp)
+ return -1;
+
+ ptp->marker_fd = -1;
+ ptp->debug_fd = -1;
+
+ path = tracefs_instance_get_dir(clock_context->instance);
+ if (!path)
+ goto error;
+ ptp->tep = tracefs_local_events_system(path, systems);
+ tracefs_put_tracing_file(path);
+ if (!ptp->tep)
+ goto error;
+ raw = tep_find_event_by_name(ptp->tep, "ftrace", "raw_data");
+ if (!raw)
+ goto error;
+ ptp->id = tep_find_field(raw, "id");
+ if (!ptp->id)
+ goto error;
+ ptp->raw_id = raw->id;
+
+ tep_set_file_bigendian(ptp->tep, tracecmd_host_bigendian());
+ tep_set_local_bigendian(ptp->tep, tracecmd_host_bigendian());
+
+ path = tracefs_instance_get_file(clock_context->instance, "trace_marker_raw");
+ if (!path)
+ goto error;
+ ptp->marker_fd = open(path, O_WRONLY);
+ tracefs_put_tracing_file(path);
+
+ clock_context->proto_data = ptp;
+
+#ifdef TSYNC_DEBUG
+ if (clock_context->is_server) {
+ char buff[256];
+ int res_fd;
+
+ sprintf(buff, "res-cid%d.txt", clock_context->remote_cid);
+
+ res_fd = open(buff, O_CREAT|O_WRONLY|O_TRUNC, 0644);
+ if (res_fd > 0)
+ close(res_fd);
+ }
+#endif
+
+ return 0;
+
+error:
+ if (ptp) {
+ tep_free(ptp->tep);
+ if (ptp->marker_fd >= 0)
+ close(ptp->marker_fd);
+ }
+ free(ptp);
+ return -1;
+}
+
+static int ptp_clock_sync_free(struct tracecmd_time_sync *tsync)
+{
+ struct clock_sync_context *clock_context;
+ struct ptp_clock_sync *ptp;
+
+ if (!tsync || !tsync->context)
+ return -1;
+ clock_context = (struct clock_sync_context *)tsync->context;
+
+ if (clock_context && clock_context->proto_data) {
+ ptp = (struct ptp_clock_sync *)clock_context->proto_data;
+ tep_free(ptp->tep);
+ if (ptp->marker_fd >= 0)
+ close(ptp->marker_fd);
+ if (ptp->debug_fd >= 0)
+ close(ptp->debug_fd);
+ free(clock_context->proto_data);
+ clock_context->proto_data = NULL;
+ }
+ return 0;
+}
+
+/* Save the timestamps of sent ('s') and returned ('r') probes in the
+ * ctx->msg.samples[] array. Depending of the context (server or client), there
+ * may be only returned probes, or both sent and returned probes. The returned
+ * probes are saved first in the array, after them are the sent probes.
+ * Depending of the context, the array can be with size:
+ * [0 .. max data.count] - holds only returned probes
+ * [0 .. 2 * max data.count] - holds both returned and sent probes
+ */
+static void ptp_probe_store(struct ptp_markers_context *ctx,
+ struct ptp_marker *marker,
+ unsigned long long ts)
+{
+ int index = -1;
+
+ if (marker->data.packet_id == 'r' &&
+ marker->data.count <= ctx->size) {
+ index = marker->data.count - 1;
+ } else if (marker->data.packet_id == 's' &&
+ marker->data.count * 2 <= ctx->size){
+ index = ctx->size / 2 + marker->data.count - 1;
+ }
+
+ if (index >= 0) {
+ ctx->msg.samples[index].id = marker->data.count;
+ ctx->msg.samples[index].ts = ts;
+ ctx->msg.count++;
+ }
+}
+
+static int ptp_marker_find(struct tep_event *event, struct tep_record *record,
+ int cpu, void *context)
+{
+ struct ptp_markers_context *ctx;
+ struct ptp_marker *marker;
+
+ ctx = (struct ptp_markers_context *)context;
+
+ /* Make sure this is our event */
+ if (event->id != ctx->ptp->raw_id || !ctx->ptp->id)
+ return 0;
+ if (record->size >= (ctx->ptp->id->offset + sizeof(struct ptp_marker))) {
+ marker = (struct ptp_marker *)(record->data + ctx->ptp->id->offset);
+ if (marker->data.local_cid == ctx->clock->local_cid &&
+ marker->data.remote_cid == ctx->clock->remote_cid &&
+ marker->series_id == ctx->ptp->series_id &&
+ marker->data.count)
+ ptp_probe_store(ctx, marker, record->ts);
+ }
+
+ return 0;
+}
+
+static inline bool good_probe(struct ptp_clock_sample *server_sample,
+ struct ptp_clock_sample *send_sample,
+ struct ptp_clock_sample *client_sample,
+ int *bad_probes)
+{
+ if (server_sample->ts && send_sample->ts && client_sample->ts &&
+ server_sample->id == send_sample->id &&
+ server_sample->id == client_sample->id)
+ return true;
+ (*bad_probes)++;
+ return false;
+}
+
+static int ptp_calc_offset_fastest(struct clock_sync_context *clock,
+ struct ptp_clock_result_msg *server,
+ struct ptp_clock_result_msg *client,
+ long long *offset_ret, long long *ts_ret,
+ int *bad_probes)
+{
+ struct ptp_clock_sample *sample_send;
+ long long delta_min = LLONG_MAX;
+ long long offset = 0;
+ long long delta = 0;
+ long long ts = 0;
+ int max_i;
+ int i;
+
+ *bad_probes = 0;
+ sample_send = server->samples + (server->count / 2);
+ max_i = server->count / 2 < client->count ?
+ server->count / 2 : client->count;
+ for (i = 0; i < max_i; i++) {
+ if (!good_probe(&server->samples[i], &sample_send[i],
+ &client->samples[i], bad_probes))
+ continue;
+ ts = (sample_send[i].ts + server->samples[i].ts) / 2;
+ offset = client->samples[i].ts - ts;
+
+ delta = server->samples[i].ts - sample_send[i].ts;
+ if (delta_min > delta) {
+ delta_min = delta;
+ *offset_ret = offset;
+ *ts_ret = ts;
+ }
+#ifdef TSYNC_DEBUG
+ {
+ struct ptp_clock_sync *ptp;
+
+ ptp = (struct ptp_clock_sync *)clock->proto_data;
+ if (ptp && ptp->debug_fd > 0) {
+ char buff[256];
+
+ sprintf(buff, "%lld %lld %lld\n",
+ ts, client->samples[i].ts, offset);
+ write(ptp->debug_fd, buff, strlen(buff));
+ }
+ }
+#endif
+ }
+
+ return 0;
+}
+
+static int ptp_calc_offset_hist(struct clock_sync_context *clock,
+ struct ptp_clock_result_msg *server,
+ struct ptp_clock_result_msg *client,
+ long long *offset_ret, long long *ts_ret,
+ int *bad_probes)
+{
+ struct ptp_clock_sample *sample_send;
+ long long timestamps[PTP_SYNC_LOOP];
+ long long offsets[PTP_SYNC_LOOP];
+ long long offset_min = LLONG_MAX;
+ long long offset_max = 0;
+ int hist[PTP_SYNC_LOOP];
+ int ind, max = 0;
+ long long bin;
+ int i, k = 0;
+
+ *bad_probes = 0;
+ memset(hist, 0, sizeof(int) * PTP_SYNC_LOOP);
+ sample_send = server->samples + (server->count / 2);
+ for (i = 0; i * 2 < server->count && i < client->count; i++) {
+ if (!good_probe(&server->samples[i], &sample_send[i],
+ &client->samples[i], bad_probes))
+ continue;
+ timestamps[k] = (sample_send[i].ts + server->samples[i].ts) / 2;
+ offsets[k] = client->samples[i].ts - timestamps[k];
+ if (offset_max < llabs(offsets[k]))
+ offset_max = llabs(offsets[k]);
+ if (offset_min > llabs(offsets[k]))
+ offset_min = llabs(offsets[k]);
+#ifdef TSYNC_DEBUG
+ {
+ struct ptp_clock_sync *ptp;
+
+ ptp = (struct ptp_clock_sync *)clock->proto_data;
+
+ if (ptp && ptp->debug_fd > 0) {
+ char buff[256];
+
+ sprintf(buff, "%lld %lld %lld\n",
+ timestamps[k],
+ client->samples[i].ts, offsets[k]);
+ write(ptp->debug_fd, buff, strlen(buff));
+ }
+ }
+#endif
+ k++;
+ }
+
+ bin = (offset_max - offset_min) / PTP_SYNC_LOOP;
+ for (i = 0; i < k; i++) {
+ ind = (llabs(offsets[i]) - offset_min) / bin;
+ if (ind < PTP_SYNC_LOOP) {
+ hist[ind]++;
+ if (max < hist[ind]) {
+ max = hist[ind];
+ *offset_ret = offsets[i];
+ *ts_ret = timestamps[i];
+ }
+ }
+ }
+
+ return 0;
+}
+
+static void ntoh_ptp_results(struct ptp_clock_result_msg *msg)
+{
+ int i;
+
+ msg->count = ntohl(msg->count);
+ for (i = 0; i < msg->count; i++) {
+ msg->samples[i].id = ntohl(msg->samples[i].id);
+ msg->samples[i].ts = ntohll(msg->samples[i].ts);
+ }
+ msg->series_id = ntohl(msg->series_id);
+}
+
+
+static void hton_ptp_results(struct ptp_clock_result_msg *msg)
+{
+ int i;
+
+ for (i = 0; i < msg->count; i++) {
+ msg->samples[i].id = htonl(msg->samples[i].id);
+ msg->samples[i].ts = htonll(msg->samples[i].ts);
+ }
+ msg->series_id = htonl(msg->series_id);
+ msg->count = htonl(msg->count);
+}
+
+static inline void ptp_track_clock(struct ptp_markers_context *ctx,
+ struct ptp_marker *marker)
+{
+ if (ctx->ptp->flags & PTP_FLAG_USE_MARKER) {
+ write(ctx->ptp->marker_fd, marker, sizeof(struct ptp_marker));
+ } else {
+ struct timespec clock;
+ unsigned long long ts;
+
+ clock_gettime(CLOCK_MONOTONIC_RAW, &clock);
+ ts = clock.tv_sec * 1000000000LL;
+ ts += clock.tv_nsec;
+ ptp_probe_store(ctx, marker, ts);
+ }
+}
+
+static int ptp_clock_client(struct tracecmd_time_sync *tsync,
+ long long *offset, long long *timestamp)
+{
+ char sync_proto[TRACECMD_TSYNC_PNAME_LENGTH];
+ struct clock_sync_context *clock_context;
+ struct ptp_clock_offset_msg res_offset;
+ struct ptp_clock_start_msg start;
+ struct ptp_markers_context ctx;
+ struct ptp_clock_sync *ptp;
+ struct ptp_marker marker;
+ unsigned int sync_msg;
+ unsigned int size;
+ char *msg;
+ int count;
+ int ret;
+
+ if (!tsync || !tsync->context || !tsync->msg_handle)
+ return -1;
+
+ clock_context = (struct clock_sync_context *)tsync->context;
+ if (clock_context->proto_data == NULL)
+ return -1;
+
+ ptp = (struct ptp_clock_sync *)clock_context->proto_data;
+ size = sizeof(start);
+ msg = (char *)&start;
+ ret = tracecmd_msg_recv_time_sync(tsync->msg_handle,
+ sync_proto, &sync_msg,
+ &size, &msg);
+ if (ret || strncmp(sync_proto, PTP_NAME, TRACECMD_TSYNC_PNAME_LENGTH) ||
+ sync_msg != PTP_SYNC_PKT_START)
+ return -1;
+ ret = tracecmd_msg_send_time_sync(tsync->msg_handle, PTP_NAME,
+ PTP_SYNC_PKT_START, sizeof(start),
+ (char *)&start);
+ marker.data.local_cid = clock_context->local_cid;
+ marker.data.remote_cid = clock_context->remote_cid;
+ marker.series_id = ntohl(start.series_id);
+ marker.data.packet_id = 'r';
+ ptp->series_id = marker.series_id;
+ ptp->flags = ntohl(start.flags);
+ msg = (char *)&count;
+ size = sizeof(count);
+ ctx.msg.count = 0;
+ ctx.size = PTP_SYNC_LOOP;
+ ctx.ptp = ptp;
+ ctx.clock = clock_context;
+ ctx.msg.series_id = ptp->series_id;
+ while (true) {
+ count = 0;
+ ret = tracecmd_msg_recv_time_sync(tsync->msg_handle,
+ sync_proto, &sync_msg,
+ &size, &msg);
+ if (ret || strncmp(sync_proto, PTP_NAME, TRACECMD_TSYNC_PNAME_LENGTH) ||
+ sync_msg != PTP_SYNC_PKT_PROBE || !ntohl(count))
+ break;
+ marker.data.count = ntohl(count);
+ ptp_track_clock(&ctx, &marker);
+ ret = tracecmd_msg_send_time_sync(tsync->msg_handle, PTP_NAME,
+ PTP_SYNC_PKT_PROBE,
+ sizeof(count), (char *)&count);
+ if (ret)
+ break;
+ }
+
+ if (strncmp(sync_proto, PTP_NAME, TRACECMD_TSYNC_PNAME_LENGTH) ||
+ sync_msg != PTP_SYNC_PKT_END)
+ return -1;
+
+ if (ptp->flags & PTP_FLAG_USE_MARKER)
+ tracefs_iterate_raw_events(ptp->tep, clock_context->instance,
+ NULL, 0, ptp_marker_find, &ctx);
+
+ hton_ptp_results(&ctx.msg);
+ ret = tracecmd_msg_send_time_sync(tsync->msg_handle, PTP_NAME,
+ PTP_SYNC_PKT_PROBES,
+ sizeof(ctx.msg), (char *)&ctx.msg);
+
+ msg = (char *)&res_offset;
+ size = sizeof(res_offset);
+ ret = tracecmd_msg_recv_time_sync(tsync->msg_handle,
+ sync_proto, &sync_msg,
+ &size, (char **)&msg);
+ if (ret || strncmp(sync_proto, PTP_NAME, TRACECMD_TSYNC_PNAME_LENGTH) ||
+ sync_msg != PTP_SYNC_PKT_OFFSET)
+ return -1;
+
+ *offset = ntohll(res_offset.offset);
+ *timestamp = ntohll(res_offset.ts);
+
+ return 0;
+}
+
+
+static int ptp_clock_server(struct tracecmd_time_sync *tsync,
+ long long *offset, long long *timestamp)
+{
+ char sync_proto[TRACECMD_TSYNC_PNAME_LENGTH];
+ struct ptp_clock_result_msg *results = NULL;
+ struct clock_sync_context *clock_context;
+ struct ptp_clock_offset_msg res_offset;
+ struct ptp_clock_start_msg start;
+ struct ptp_markers_context ctx;
+ int sync_loop = PTP_SYNC_LOOP;
+ struct ptp_clock_sync *ptp;
+ struct ptp_marker marker;
+ unsigned int sync_msg;
+ unsigned int size;
+ int bad_probes;
+ int count = 1;
+ int msg_count;
+ int msg_ret;
+ char *msg;
+ int ret;
+
+ if (!tsync || !tsync->context || !tsync->msg_handle)
+ return -1;
+
+ clock_context = (struct clock_sync_context *)tsync->context;
+ if (clock_context->proto_data == NULL)
+ return -1;
+
+ ptp = (struct ptp_clock_sync *)clock_context->proto_data;
+ ptp->flags = ptp_flags;
+ memset(&start, 0, sizeof(start));
+ start.series_id = htonl(ptp->series_id + 1);
+ start.flags = htonl(ptp->flags);
+ ret = tracecmd_msg_send_time_sync(tsync->msg_handle, PTP_NAME,
+ PTP_SYNC_PKT_START, sizeof(start),
+ (char *)&start);
+ if (!ret)
+ ret = tracecmd_msg_recv_time_sync(tsync->msg_handle,
+ sync_proto, &sync_msg,
+ NULL, NULL);
+ if (ret || strncmp(sync_proto, PTP_NAME, TRACECMD_TSYNC_PNAME_LENGTH) ||
+ sync_msg != PTP_SYNC_PKT_START)
+ return -1;
+
+ tracefs_instance_file_write(clock_context->instance, "trace", "\0");
+
+ ptp->series_id++;
+ marker.data.local_cid = clock_context->local_cid;
+ marker.data.remote_cid = clock_context->remote_cid;
+ marker.series_id = ptp->series_id;
+ msg = (char *)&msg_ret;
+ size = sizeof(msg_ret);
+ ctx.size = 2*PTP_SYNC_LOOP;
+ ctx.ptp = ptp;
+ ctx.clock = clock_context;
+ ctx.msg.count = 0;
+ ctx.msg.series_id = ptp->series_id;
+ do {
+ marker.data.count = count++;
+ marker.data.packet_id = 's';
+ msg_count = htonl(marker.data.count);
+ ptp_track_clock(&ctx, &marker);
+ ret = tracecmd_msg_send_time_sync(tsync->msg_handle, PTP_NAME,
+ PTP_SYNC_PKT_PROBE,
+ sizeof(msg_count),
+ (char *)&msg_count);
+ if (!ret)
+ ret = tracecmd_msg_recv_time_sync(tsync->msg_handle,
+ sync_proto, &sync_msg,
+ &size, &msg);
+
+ marker.data.packet_id = 'r';
+ ptp_track_clock(&ctx, &marker);
+ if (ret || strncmp(sync_proto, PTP_NAME, TRACECMD_TSYNC_PNAME_LENGTH) ||
+ sync_msg != PTP_SYNC_PKT_PROBE ||
+ ntohl(msg_ret) != marker.data.count)
+ break;
+ } while (--sync_loop);
+
+ if (sync_loop)
+ return -1;
+
+ ret = tracecmd_msg_send_time_sync(tsync->msg_handle, PTP_NAME,
+ PTP_SYNC_PKT_END, 0, NULL);
+
+ size = 0;
+ ret = tracecmd_msg_recv_time_sync(tsync->msg_handle,
+ sync_proto, &sync_msg,
+ &size, (char **)&results);
+ if (ret || strncmp(sync_proto, PTP_NAME, TRACECMD_TSYNC_PNAME_LENGTH) ||
+ sync_msg != PTP_SYNC_PKT_PROBES || size == 0 || results == NULL)
+ return -1;
+
+ ntoh_ptp_results(results);
+ if (ptp->flags & PTP_FLAG_USE_MARKER)
+ tracefs_iterate_raw_events(ptp->tep, clock_context->instance,
+ NULL, 0, ptp_marker_find, &ctx);
+ if (ptp->flags & PTP_FLAG_FASTEST_RESPONSE)
+ ptp_calc_offset_fastest(clock_context, &ctx.msg, results, offset,
+ timestamp, &bad_probes);
+ else
+ ptp_calc_offset_hist(clock_context, &ctx.msg, results, offset,
+ timestamp, &bad_probes);
+#ifdef TSYNC_DEBUG
+ {
+ char buff[256];
+ int res_fd;
+
+ sprintf(buff, "res-cid%d.txt", clock_context->remote_cid);
+
+ res_fd = open(buff, O_WRONLY|O_APPEND, 0644);
+ if (res_fd > 0) {
+ if (*offset && *timestamp) {
+ sprintf(buff, "%d %lld %lld\n",
+ ptp->series_id, *offset, *timestamp);
+ write(res_fd, buff, strlen(buff));
+ }
+ close(res_fd);
+ }
+
+ printf("\n calculated offset %d: %lld, %d probes, filtered out %d, PTP flags 0x%X\n\r",
+ ptp->series_id, *offset, results->count, bad_probes, ptp->flags);
+ if (ptp && ptp->debug_fd > 0) {
+ sprintf(buff, "%lld %lld 0\n", *offset, *timestamp);
+ write(ptp->debug_fd, buff, strlen(buff));
+ close(ptp->debug_fd);
+ ptp->debug_fd = -1;
+ }
+
+ }
+#endif
+
+ res_offset.offset = htonll(*offset);
+ res_offset.ts = htonll(*timestamp);
+ ret = tracecmd_msg_send_time_sync(tsync->msg_handle, PTP_NAME,
+ PTP_SYNC_PKT_OFFSET,
+ sizeof(res_offset),
+ (char *)&res_offset);
+
+ free(results);
+ return 0;
+}
+
+static int ptp_clock_sync_calc(struct tracecmd_time_sync *tsync,
+ long long *offset, long long *scaling,
+ long long *timestamp, unsigned int cpu)
+{
+ struct clock_sync_context *clock_context;
+ int ret;
+
+ if (!tsync || !tsync->context)
+ return -1;
+ clock_context = (struct clock_sync_context *)tsync->context;
+
+#ifdef TSYNC_DEBUG
+ if (clock_context->is_server) {
+ struct ptp_clock_sync *ptp;
+ char buff[256];
+
+ ptp = (struct ptp_clock_sync *)clock_context->proto_data;
+ if (ptp->debug_fd > 0)
+ close(ptp->debug_fd);
+ sprintf(buff, "s-cid%d_%d.txt",
+ clock_context->remote_cid, ptp->series_id+1);
+ ptp->debug_fd = open(buff, O_CREAT|O_WRONLY|O_TRUNC, 0644);
+ }
+#endif
+
+ if (scaling)
+ *scaling = 1;
+ if (clock_context->is_server)
+ ret = ptp_clock_server(tsync, offset, timestamp);
+ else
+ ret = ptp_clock_client(tsync, offset, timestamp);
+
+ return ret;
+}
+
+int ptp_clock_sync_register(void)
+{
+ return tracecmd_tsync_proto_register(PTP_NAME, PTP_ACCURACY,
+ TRACECMD_TIME_SYNC_ROLE_GUEST |
+ TRACECMD_TIME_SYNC_ROLE_HOST,
+ 0, TRACECMD_TSYNC_FLAG_INTERPOLATE,
+ ptp_clock_sync_init,
+ ptp_clock_sync_free,
+ ptp_clock_sync_calc);
+
+}
+
+int ptp_clock_sync_unregister(void)
+{
+ return tracecmd_tsync_proto_unregister(PTP_NAME);
+}
diff --git a/lib/trace-cmd/trace-timesync.c b/lib/trace-cmd/trace-timesync.c
index 556004f1..ada7ddb6 100644
--- a/lib/trace-cmd/trace-timesync.c
+++ b/lib/trace-cmd/trace-timesync.c
@@ -64,7 +64,9 @@ static struct tsync_proto *tsync_proto_find(const char *proto_name)
*/
void tracecmd_tsync_init(void)
{
-
+#ifdef VSOCK
+ ptp_clock_sync_register();
+#endif
}
int tracecmd_tsync_proto_register(const char *proto_name, int accuracy, int roles,
--
2.30.2
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v33 4/5] trace-cmd: Debug scripts for PTP-like algorithm for host - guest timestamp synchronization
2021-03-25 7:14 [PATCH v33 0/5] Timestamp synchronization of host - guest tracing session Tzvetomir Stoyanov (VMware)
` (2 preceding siblings ...)
2021-03-25 7:14 ` [PATCH v33 3/5] trace-cmd: PTP-like algorithm for host - guest timestamp synchronization Tzvetomir Stoyanov (VMware)
@ 2021-03-25 7:14 ` Tzvetomir Stoyanov (VMware)
2021-03-25 7:14 ` [PATCH v33 5/5] trace-cmd [POC]: Add KVM timestamp synchronization plugin Tzvetomir Stoyanov (VMware)
4 siblings, 0 replies; 7+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2021-03-25 7:14 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel, stefano.devenuto99
These scripts can be used to visualise debug files, written when the PTP-like algorithm
is compiled with TSYNC_DEBUG defined. The files are located in the guest machine:
s-cid*.txt - For each offset calculation: host and guest clocks and calculated offset.
res-cid*.txt - For each tracing session: all calculated clock offsets.
tsync_hist.py plots a histogram, using data from a s-cid*.txt file:
"python tsync_hist.py s-cid2_1.txt"
tsync_res.py plots a line, using data from res-cid*.txt file:
"python tsync_res.py res-cid2.txt"
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
scripts/debug/tsync_hist.py | 57 +++++++++++++++++++++++++++++++++++++
scripts/debug/tsync_readme | 12 ++++++++
scripts/debug/tsync_res.py | 46 ++++++++++++++++++++++++++++++
3 files changed, 115 insertions(+)
create mode 100644 scripts/debug/tsync_hist.py
create mode 100644 scripts/debug/tsync_readme
create mode 100644 scripts/debug/tsync_res.py
diff --git a/scripts/debug/tsync_hist.py b/scripts/debug/tsync_hist.py
new file mode 100644
index 00000000..819d1e8f
--- /dev/null
+++ b/scripts/debug/tsync_hist.py
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2019, VMware Inc, Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
+# Copyright (C) 2019, VMware Inc, Yordan Karadzhov <ykaradzhov@vmware.com>
+
+
+import matplotlib.pyplot as plt
+import matplotlib.lines as mlines
+import numpy as np
+import sys
+
+def newline(p1, p2):
+ ax = plt.gca()
+ xmin, xmax = ax.get_xbound()
+
+ if(p2[0] == p1[0]):
+ xmin = xmax = p1[0]
+ ymin, ymax = ax.get_ybound()
+ else:
+ ymax = p1[1]+(p2[1]-p1[1])/(p2[0]-p1[0])*(xmax-p1[0])
+ ymin = p1[1]+(p2[1]-p1[1])/(p2[0]-p1[0])*(xmin-p1[0])
+
+ l = mlines.Line2D([xmin,xmax], [ymin,ymax], color='red')
+ ax.add_line(l)
+ return l
+
+
+data = np.loadtxt(fname = sys.argv[1])
+selected_ts = data[-1, 1]
+selected_ofs = data[-1, 0]
+data = data[:-1,:]
+
+x = data[:, 1] - data[:, 0]
+
+mean = x.mean()
+std = x.std()
+
+num_bins = 500
+min = x.min() #+ .4 * (x.max() - x.min())
+max = x.max() #- .4 * (x.max() - x.min())
+bins = np.linspace(min, max, num_bins, endpoint = False, dtype=int)
+
+fig, ax = plt.subplots()
+
+# the histogram of the data
+n, bins, patches = ax.hist(x, bins, histtype=u'step');
+
+ax.set_xlabel('clock offset [$\mu$s]')
+ax.set_ylabel('entries')
+ax.set_title("$\sigma$=%i" % std)
+
+x1, y1 = [selected_ofs, min], [selected_ofs, max]
+newline(x1, y1)
+
+# Tweak spacing to prevent clipping of ylabel
+fig.tight_layout()
+plt.show()
diff --git a/scripts/debug/tsync_readme b/scripts/debug/tsync_readme
new file mode 100644
index 00000000..f3ebb25d
--- /dev/null
+++ b/scripts/debug/tsync_readme
@@ -0,0 +1,12 @@
+PTP-like algorithm debug
+========================
+
+tsync_*.py scripts can be used to visualise debug files, written when the PTP-like algorithm
+is compiled with TSYNC_DEBUG defined. The files are located in the guest machine:
+ s-cid*.txt - For each offset calculation: host and guest clocks and calculated offset.
+ res-cid*.txt - For each tracing session: all calculated clock offsets.
+
+tsync_hist.py plots a histogram, using data from a s-cid*.txt file:
+ "python tsync_hist.py s-cid2_1.txt"
+tsync_res.py plots a line, using data from res-cid*.txt file:
+ "python tsync_res.py res-cid2.txt"
diff --git a/scripts/debug/tsync_res.py b/scripts/debug/tsync_res.py
new file mode 100644
index 00000000..7d109863
--- /dev/null
+++ b/scripts/debug/tsync_res.py
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2019, VMware Inc, Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
+# Copyright (C) 2019, VMware Inc, Yordan Karadzhov <ykaradzhov@vmware.com>
+
+
+import matplotlib.pyplot as plt
+import matplotlib.lines as mlines
+import numpy as np
+import sys
+
+def newline(p1, p2):
+ ax = plt.gca()
+ xmin, xmax = ax.get_xbound()
+
+ if(p2[0] == p1[0]):
+ xmin = xmax = p1[0]
+ ymin, ymax = ax.get_ybound()
+ else:
+ ymax = p1[1]+(p2[1]-p1[1])/(p2[0]-p1[0])*(xmax-p1[0])
+ ymin = p1[1]+(p2[1]-p1[1])/(p2[0]-p1[0])*(xmin-p1[0])
+
+ l = mlines.Line2D([xmin,xmax], [ymin,ymax], color='red')
+ ax.add_line(l)
+ return l
+
+data = np.loadtxt(fname = sys.argv[1])
+x = data[:, 0]
+y = data[:, 1]
+
+fig, ax = plt.subplots()
+
+ax.set_xlabel('samples (t)')
+ax.set_ylabel('clock offset')
+ax.set_title("$\delta$=%i ns" % (max(y) - min(y)))
+
+l = mlines.Line2D(x, y)
+ax.add_line(l)
+ax.set_xlim(min(x), max(x))
+ax.set_ylim(min(y), max(y) )
+
+print(min(y), max(y), max(y) - min(y))
+
+# Tweak spacing to prevent clipping of ylabel
+fig.tight_layout()
+plt.show()
--
2.30.2
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v33 5/5] trace-cmd [POC]: Add KVM timestamp synchronization plugin
2021-03-25 7:14 [PATCH v33 0/5] Timestamp synchronization of host - guest tracing session Tzvetomir Stoyanov (VMware)
` (3 preceding siblings ...)
2021-03-25 7:14 ` [PATCH v33 4/5] trace-cmd: Debug scripts for " Tzvetomir Stoyanov (VMware)
@ 2021-03-25 7:14 ` Tzvetomir Stoyanov (VMware)
2021-03-26 22:17 ` Steven Rostedt
4 siblings, 1 reply; 7+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2021-03-25 7:14 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel, stefano.devenuto99
Added new timestamp synchronization plugin for KVM hosts. It reads the
clock offsets directly from the KVM debug filesystem, if available.
The plugin works only with x86-tsc ftrace clock.
Note: KVM clock scaling is not supported yet. If a non-default KVM
scaling is detected, the KVM plugin is not used for timestamp
synchronization.
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
lib/trace-cmd/Makefile | 1 +
lib/trace-cmd/include/trace-tsync-local.h | 1 +
lib/trace-cmd/trace-timesync-kvm.c | 533 ++++++++++++++++++++++
lib/trace-cmd/trace-timesync.c | 1 +
4 files changed, 536 insertions(+)
create mode 100644 lib/trace-cmd/trace-timesync-kvm.c
diff --git a/lib/trace-cmd/Makefile b/lib/trace-cmd/Makefile
index 486ea7d1..afd74e1d 100644
--- a/lib/trace-cmd/Makefile
+++ b/lib/trace-cmd/Makefile
@@ -23,6 +23,7 @@ endif
OBJS += trace-timesync.o
ifeq ($(VSOCK_DEFINED), 1)
OBJS += trace-timesync-ptp.o
+OBJS += trace-timesync-kvm.o
endif
# Additional util objects
diff --git a/lib/trace-cmd/include/trace-tsync-local.h b/lib/trace-cmd/include/trace-tsync-local.h
index b3a3bdfc..7e56d187 100644
--- a/lib/trace-cmd/include/trace-tsync-local.h
+++ b/lib/trace-cmd/include/trace-tsync-local.h
@@ -65,5 +65,6 @@ int tracecmd_tsync_proto_register(const char *proto_name, int accuracy, int role
int tracecmd_tsync_proto_unregister(char *proto_name);
int ptp_clock_sync_register(void);
+int kvm_clock_sync_register(void);
#endif /* _TRACE_TSYNC_LOCAL_H */
diff --git a/lib/trace-cmd/trace-timesync-kvm.c b/lib/trace-cmd/trace-timesync-kvm.c
new file mode 100644
index 00000000..c229c2d7
--- /dev/null
+++ b/lib/trace-cmd/trace-timesync-kvm.c
@@ -0,0 +1,533 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ * Copyright (C) 2020, VMware, Tzvetomir Stoyanov tz.stoyanov@gmail.com>
+ *
+ */
+
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <dirent.h>
+#include <ctype.h>
+
+#include "trace-cmd.h"
+#include "trace-cmd-private.h"
+#include "tracefs.h"
+#include "trace-tsync-local.h"
+
+#define KVM_DEBUG_FS "/sys/kernel/debug/kvm"
+#define KVM_DEBUG_OFFSET_FILE "tsc-offset"
+#define KVM_DEBUG_SCALING_FILE "tsc-scaling-ratio"
+#define KVM_DEBUG_VCPU_DIR "vcpu"
+
+/* default KVM scaling values, taken from the Linux kernel */
+#define KVM_SCALING_AMD_DEFAULT (1ULL<<32)
+#define KVM_SCALING_INTEL_DEFAULT (1ULL<<48)
+
+#define KVM_SYNC_PKT_REQUEST 1
+#define KVM_SYNC_PKT_RESPONSE 2
+
+typedef __s64 s64;
+
+#define KVM_ACCURACY 0
+#define KVM_NAME "kvm"
+
+struct kvm_clock_sync {
+ int vcpu_count;
+ char **vcpu_offsets;
+ char **vcpu_scalings;
+ int marker_fd;
+ struct tep_handle *tep;
+ int raw_id;
+ unsigned long long ts;
+};
+
+struct kvm_clock_offset_msg {
+ s64 ts;
+ s64 offset;
+ s64 scaling;
+};
+
+static int read_ll_form_file(char *file, long long *res)
+{
+ char buf[32];
+ int ret;
+ int fd;
+
+ if (!file)
+ return -1;
+ fd = open(file, O_RDONLY | O_NONBLOCK);
+ if (fd < 0)
+ return -1;
+ ret = read(fd, buf, 32);
+ close(fd);
+ if (ret <= 0)
+ return -1;
+
+ *res = strtoll(buf, NULL, 10);
+
+ return 0;
+}
+
+static bool kvm_scaling_check_vm_cpu(char *vname, char *cpu)
+{
+ long long scaling;
+ char *path;
+ int ret;
+
+ if (asprintf(&path, "%s/%s/%s", vname, cpu, KVM_DEBUG_SCALING_FILE) < 0)
+ return true;
+ ret = read_ll_form_file(path, &scaling);
+ free(path);
+
+ /*
+ * If there is a scaling, different from the default -
+ * return false, not supported.
+ */
+ if (!ret &&
+ scaling != KVM_SCALING_AMD_DEFAULT && scaling != KVM_SCALING_INTEL_DEFAULT)
+ return false;
+
+ return true;
+}
+
+static bool kvm_scaling_check_vm(char *name)
+{
+ struct dirent *entry;
+ char *vdir;
+ DIR *dir;
+
+ if (asprintf(&vdir, "%s/%s", KVM_DEBUG_FS, name) < 0)
+ return true;
+
+ dir = opendir(vdir);
+ if (!dir) {
+ free(vdir);
+ return true;
+ }
+ while ((entry = readdir(dir))) {
+ if (entry->d_type == DT_DIR && !strncmp(entry->d_name, "vcpu", 4) &&
+ !kvm_scaling_check_vm_cpu(vdir, entry->d_name))
+ break;
+ }
+
+ closedir(dir);
+ free(vdir);
+ return entry == NULL;
+}
+static bool kvm_scaling_check(void)
+{
+ struct dirent *entry;
+ DIR *dir;
+
+ dir = opendir(KVM_DEBUG_FS);
+ if (!dir)
+ return true;
+
+ while ((entry = readdir(dir))) {
+ if (entry->d_type == DT_DIR && isdigit(entry->d_name[0]) &&
+ !kvm_scaling_check_vm(entry->d_name))
+ break;
+ }
+ closedir(dir);
+ return entry == NULL;
+}
+
+static bool kvm_support_check(bool guest)
+{
+ struct stat st;
+ int ret;
+
+ if (guest)
+ return true;
+
+ ret = stat(KVM_DEBUG_FS, &st);
+ if (ret < 0)
+ return false;
+
+ if (!S_ISDIR(st.st_mode))
+ return false;
+
+ return kvm_scaling_check();
+}
+
+static int kvm_open_vcpu_dir(struct kvm_clock_sync *kvm, int cpu, char *dir_str)
+{
+ struct dirent *entry;
+ char path[PATH_MAX];
+ DIR *dir;
+
+ dir = opendir(dir_str);
+ if (!dir)
+ goto error;
+ while ((entry = readdir(dir))) {
+ if (entry->d_type != DT_DIR) {
+ if (!strncmp(entry->d_name, KVM_DEBUG_OFFSET_FILE,
+ strlen(KVM_DEBUG_OFFSET_FILE))) {
+ snprintf(path, sizeof(path), "%s/%s",
+ dir_str, entry->d_name);
+ kvm->vcpu_offsets[cpu] = strdup(path);
+ }
+ if (!strncmp(entry->d_name, KVM_DEBUG_SCALING_FILE,
+ strlen(KVM_DEBUG_SCALING_FILE))) {
+ snprintf(path, sizeof(path), "%s/%s",
+ dir_str, entry->d_name);
+ kvm->vcpu_scalings[cpu] = strdup(path);
+ }
+ }
+ }
+ if (!kvm->vcpu_offsets[cpu])
+ goto error;
+ closedir(dir);
+ return 0;
+
+error:
+ if (dir)
+ closedir(dir);
+ free(kvm->vcpu_offsets[cpu]);
+ kvm->vcpu_offsets[cpu] = NULL;
+ free(kvm->vcpu_scalings[cpu]);
+ kvm->vcpu_scalings[cpu] = NULL;
+ return -1;
+}
+
+static int kvm_open_debug_files(struct kvm_clock_sync *kvm, int pid)
+{
+ char *vm_dir_str = NULL;
+ struct dirent *entry;
+ char *pid_str = NULL;
+ char path[PATH_MAX];
+ long vcpu;
+ DIR *dir;
+ int i;
+
+ dir = opendir(KVM_DEBUG_FS);
+ if (!dir)
+ goto error;
+ if (asprintf(&pid_str, "%d-", pid) <= 0)
+ goto error;
+ while ((entry = readdir(dir))) {
+ if (!(entry->d_type == DT_DIR &&
+ !strncmp(entry->d_name, pid_str, strlen(pid_str))))
+ continue;
+ asprintf(&vm_dir_str, "%s/%s", KVM_DEBUG_FS, entry->d_name);
+ break;
+ }
+ closedir(dir);
+ dir = NULL;
+ if (!vm_dir_str)
+ goto error;
+ dir = opendir(vm_dir_str);
+ if (!dir)
+ goto error;
+ while ((entry = readdir(dir))) {
+ if (!(entry->d_type == DT_DIR &&
+ !strncmp(entry->d_name, KVM_DEBUG_VCPU_DIR, strlen(KVM_DEBUG_VCPU_DIR))))
+ continue;
+ vcpu = strtol(entry->d_name + strlen(KVM_DEBUG_VCPU_DIR), NULL, 10);
+ if (vcpu < 0 || vcpu >= kvm->vcpu_count)
+ continue;
+ snprintf(path, sizeof(path), "%s/%s", vm_dir_str, entry->d_name);
+ if (kvm_open_vcpu_dir(kvm, vcpu, path) < 0)
+ goto error;
+ }
+ for (i = 0; i < kvm->vcpu_count; i++) {
+ if (!kvm->vcpu_offsets[i])
+ goto error;
+ }
+ closedir(dir);
+ free(pid_str);
+ free(vm_dir_str);
+ return 0;
+error:
+ free(pid_str);
+ free(vm_dir_str);
+ if (dir)
+ closedir(dir);
+ return -1;
+}
+
+static int kvm_clock_sync_init_host(struct tracecmd_time_sync *tsync,
+ struct kvm_clock_sync *kvm)
+{
+ kvm->vcpu_count = tsync->vcpu_count;
+ kvm->vcpu_offsets = calloc(kvm->vcpu_count, sizeof(char *));
+ kvm->vcpu_scalings = calloc(kvm->vcpu_count, sizeof(char *));
+ if (!kvm->vcpu_offsets || !kvm->vcpu_scalings)
+ goto error;
+ if (kvm_open_debug_files(kvm, tsync->guest_pid) < 0)
+ goto error;
+ return 0;
+
+error:
+ free(kvm->vcpu_offsets);
+ free(kvm->vcpu_scalings);
+ return -1;
+}
+
+static int kvm_clock_sync_init_guest(struct tracecmd_time_sync *tsync,
+ struct kvm_clock_sync *kvm)
+{
+ const char *systems[] = {"ftrace", NULL};
+ struct clock_sync_context *clock_context;
+ struct tep_event *raw;
+ char *path;
+
+ clock_context = (struct clock_sync_context *)tsync->context;
+ path = tracefs_instance_get_dir(clock_context->instance);
+ if (!path)
+ goto error;
+ kvm->tep = tracefs_local_events_system(path, systems);
+ tracefs_put_tracing_file(path);
+ if (!kvm->tep)
+ goto error;
+ raw = tep_find_event_by_name(kvm->tep, "ftrace", "raw_data");
+ if (!raw)
+ goto error;
+
+ kvm->raw_id = raw->id;
+ tep_set_file_bigendian(kvm->tep, tracecmd_host_bigendian());
+ tep_set_local_bigendian(kvm->tep, tracecmd_host_bigendian());
+
+ path = tracefs_instance_get_file(clock_context->instance, "trace_marker_raw");
+ if (!path)
+ goto error;
+ kvm->marker_fd = open(path, O_WRONLY);
+ tracefs_put_tracing_file(path);
+
+ return 0;
+
+error:
+ if (kvm->tep)
+ tep_free(kvm->tep);
+ if (kvm->marker_fd >= 0)
+ close(kvm->marker_fd);
+
+ return -1;
+}
+
+static int kvm_clock_sync_init(struct tracecmd_time_sync *tsync)
+{
+ struct clock_sync_context *clock_context;
+ struct kvm_clock_sync *kvm;
+ int ret;
+
+ if (!tsync || !tsync->context)
+ return -1;
+ clock_context = (struct clock_sync_context *)tsync->context;
+
+ if (!kvm_support_check(clock_context->is_guest))
+ return -1;
+ kvm = calloc(1, sizeof(struct kvm_clock_sync));
+ if (!kvm)
+ return -1;
+ kvm->marker_fd = -1;
+ if (clock_context->is_guest)
+ ret = kvm_clock_sync_init_guest(tsync, kvm);
+ else
+ ret = kvm_clock_sync_init_host(tsync, kvm);
+ if (ret < 0)
+ goto error;
+
+ clock_context->proto_data = kvm;
+ return 0;
+
+error:
+ free(kvm);
+ return -1;
+}
+
+static int kvm_clock_sync_free(struct tracecmd_time_sync *tsync)
+{
+ struct clock_sync_context *clock_context;
+ struct kvm_clock_sync *kvm = NULL;
+ int i;
+
+ clock_context = (struct clock_sync_context *)tsync->context;
+ if (clock_context)
+ kvm = (struct kvm_clock_sync *)clock_context->proto_data;
+ if (kvm) {
+ for (i = 0; i < kvm->vcpu_count; i++) {
+ free(kvm->vcpu_offsets[i]);
+ kvm->vcpu_offsets[i] = NULL;
+ free(kvm->vcpu_scalings[i]);
+ kvm->vcpu_scalings[i] = NULL;
+ }
+ if (kvm->tep)
+ tep_free(kvm->tep);
+ if (kvm->marker_fd >= 0)
+ close(kvm->marker_fd);
+ free(kvm);
+ }
+ return -1;
+}
+
+static int kvm_clock_host(struct tracecmd_time_sync *tsync,
+ long long *offset, long long *scaling,
+ long long *timestamp, unsigned int cpu)
+{
+ char sync_proto[TRACECMD_TSYNC_PNAME_LENGTH];
+ struct clock_sync_context *clock_context;
+ struct kvm_clock_offset_msg packet;
+ struct kvm_clock_sync *kvm = NULL;
+ long long kvm_scaling = 1;
+ unsigned int sync_msg;
+ long long kvm_offset;
+ unsigned int size;
+ char *msg;
+ int ret;
+
+ clock_context = (struct clock_sync_context *)tsync->context;
+ if (clock_context)
+ kvm = (struct kvm_clock_sync *)clock_context->proto_data;
+ if (!kvm || !kvm->vcpu_offsets || !kvm->vcpu_offsets[0])
+ return -1;
+ if (cpu >= kvm->vcpu_count)
+ return -1;
+ ret = read_ll_form_file(kvm->vcpu_offsets[cpu], &kvm_offset);
+ if (ret < 0)
+ return -1;
+ if (kvm->vcpu_scalings && kvm->vcpu_scalings[cpu]) {
+ read_ll_form_file(kvm->vcpu_scalings[cpu], &kvm_scaling);
+ if (kvm_scaling == KVM_SCALING_AMD_DEFAULT ||
+ kvm_scaling == KVM_SCALING_INTEL_DEFAULT)
+ kvm_scaling = 1;
+ }
+ msg = (char *)&packet;
+ size = sizeof(packet);
+ ret = tracecmd_msg_recv_time_sync(tsync->msg_handle,
+ sync_proto, &sync_msg,
+ &size, &msg);
+ if (ret || strncmp(sync_proto, KVM_NAME, TRACECMD_TSYNC_PNAME_LENGTH) ||
+ sync_msg != KVM_SYNC_PKT_REQUEST)
+ return -1;
+
+ packet.offset = -kvm_offset;
+ packet.scaling = kvm_scaling;
+ ret = tracecmd_msg_send_time_sync(tsync->msg_handle, KVM_NAME,
+ KVM_SYNC_PKT_RESPONSE, sizeof(packet),
+ (char *)&packet);
+ if (ret)
+ return -1;
+
+ *scaling = packet.scaling;
+ *offset = packet.offset;
+ *timestamp = packet.ts;
+
+ return 0;
+}
+
+#define KVM_EVENT_MARKER "kvm sync event"
+static int kvm_marker_find(struct tep_event *event, struct tep_record *record,
+ int cpu, void *context)
+{
+ struct kvm_clock_sync *kvm = (struct kvm_clock_sync *)context;
+ struct tep_format_field *field;
+ struct tep_format_field *id;
+ char *marker;
+
+ /* Make sure this is our event */
+ if (event->id != kvm->raw_id)
+ return 0;
+ id = tep_find_field(event, "id");
+ field = tep_find_field(event, "buf");
+ if (field && id &&
+ record->size >= (id->offset + strlen(KVM_EVENT_MARKER) + 1)) {
+ marker = (char *)(record->data + id->offset);
+ if (!strcmp(marker, KVM_EVENT_MARKER)) {
+ kvm->ts = record->ts;
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+
+static int kvm_clock_guest(struct tracecmd_time_sync *tsync,
+ long long *offset,
+ long long *scaling,
+ long long *timestamp)
+{
+ char sync_proto[TRACECMD_TSYNC_PNAME_LENGTH];
+ struct clock_sync_context *clock_context;
+ struct kvm_clock_offset_msg packet;
+ struct kvm_clock_sync *kvm = NULL;
+ unsigned int sync_msg;
+ unsigned int size;
+ char *msg;
+ int ret;
+
+ clock_context = (struct clock_sync_context *)tsync->context;
+ if (clock_context)
+ kvm = (struct kvm_clock_sync *)clock_context->proto_data;
+ if (!kvm)
+ return -1;
+ kvm->ts = 0;
+ memset(&packet, 0, sizeof(packet));
+ tracefs_instance_file_write(clock_context->instance, "trace", "\0");
+ write(kvm->marker_fd, KVM_EVENT_MARKER, strlen(KVM_EVENT_MARKER) + 1);
+ kvm->ts = 0;
+ tracefs_iterate_raw_events(kvm->tep, clock_context->instance,
+ NULL, 0, kvm_marker_find, kvm);
+ packet.ts = kvm->ts;
+ ret = tracecmd_msg_send_time_sync(tsync->msg_handle, KVM_NAME,
+ KVM_SYNC_PKT_REQUEST, sizeof(packet),
+ (char *)&packet);
+ if (ret)
+ return -1;
+ msg = (char *)&packet;
+ size = sizeof(packet);
+ ret = tracecmd_msg_recv_time_sync(tsync->msg_handle,
+ sync_proto, &sync_msg,
+ &size, &msg);
+ if (ret || strncmp(sync_proto, KVM_NAME, TRACECMD_TSYNC_PNAME_LENGTH) ||
+ sync_msg != KVM_SYNC_PKT_RESPONSE)
+ return -1;
+
+ *scaling = packet.scaling;
+ *offset = packet.offset;
+ *timestamp = packet.ts;
+ return 0;
+}
+
+static int kvm_clock_sync_calc(struct tracecmd_time_sync *tsync,
+ long long *offset, long long *scaling,
+ long long *timestamp, unsigned int cpu)
+{
+ struct clock_sync_context *clock_context;
+ int ret;
+
+ if (!tsync || !tsync->context)
+ return -1;
+
+ clock_context = (struct clock_sync_context *)tsync->context;
+
+ if (clock_context->is_guest)
+ ret = kvm_clock_guest(tsync, offset, scaling, timestamp);
+ else
+ ret = kvm_clock_host(tsync, offset, scaling, timestamp, cpu);
+ return ret;
+}
+
+int kvm_clock_sync_register(void)
+{
+ int role = TRACECMD_TIME_SYNC_ROLE_GUEST;
+ int clock = 0;
+
+ if (kvm_support_check(false)) {
+ role |= TRACECMD_TIME_SYNC_ROLE_HOST;
+ clock = TRACECMD_CLOCK_X86_TSC;
+ }
+ return tracecmd_tsync_proto_register(KVM_NAME, KVM_ACCURACY,
+ role, clock, 0,
+ kvm_clock_sync_init,
+ kvm_clock_sync_free,
+ kvm_clock_sync_calc);
+}
+
+int kvm_clock_sync_unregister(void)
+{
+ return tracecmd_tsync_proto_unregister(KVM_NAME);
+}
diff --git a/lib/trace-cmd/trace-timesync.c b/lib/trace-cmd/trace-timesync.c
index ada7ddb6..8b8afd01 100644
--- a/lib/trace-cmd/trace-timesync.c
+++ b/lib/trace-cmd/trace-timesync.c
@@ -66,6 +66,7 @@ void tracecmd_tsync_init(void)
{
#ifdef VSOCK
ptp_clock_sync_register();
+ kvm_clock_sync_register();
#endif
}
--
2.30.2
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v33 5/5] trace-cmd [POC]: Add KVM timestamp synchronization plugin
2021-03-25 7:14 ` [PATCH v33 5/5] trace-cmd [POC]: Add KVM timestamp synchronization plugin Tzvetomir Stoyanov (VMware)
@ 2021-03-26 22:17 ` Steven Rostedt
0 siblings, 0 replies; 7+ messages in thread
From: Steven Rostedt @ 2021-03-26 22:17 UTC (permalink / raw)
To: Tzvetomir Stoyanov (VMware); +Cc: linux-trace-devel, stefano.devenuto99
On Thu, 25 Mar 2021 09:14:13 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:
> +static int read_ll_form_file(char *file, long long *res)
Is this reading a ll form file, or is this suppose to be read ll from file?
> +{
> + char buf[32];
> + int ret;
> + int fd;
> +
> + if (!file)
> + return -1;
> + fd = open(file, O_RDONLY | O_NONBLOCK);
> + if (fd < 0)
> + return -1;
> + ret = read(fd, buf, 32);
> + close(fd);
> + if (ret <= 0)
> + return -1;
> +
> + *res = strtoll(buf, NULL, 10);
Also, if for some reason this file produced hex this wont work. Should we
just let it detect the format?
*res = strtoll(buf, NULL, 0);
This way both "10" and "0xa" would produce the same result.
-- Steve
> +
> + return 0;
> +}
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2021-03-26 22:18 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-03-25 7:14 [PATCH v33 0/5] Timestamp synchronization of host - guest tracing session Tzvetomir Stoyanov (VMware)
2021-03-25 7:14 ` [PATCH v33 1/5] trace-cmd: Add dummy function to initialize timestamp sync logic Tzvetomir Stoyanov (VMware)
2021-03-25 7:14 ` [PATCH v33 2/5] trace-cmd: Add timestamp synchronization per vCPU Tzvetomir Stoyanov (VMware)
2021-03-25 7:14 ` [PATCH v33 3/5] trace-cmd: PTP-like algorithm for host - guest timestamp synchronization Tzvetomir Stoyanov (VMware)
2021-03-25 7:14 ` [PATCH v33 4/5] trace-cmd: Debug scripts for " Tzvetomir Stoyanov (VMware)
2021-03-25 7:14 ` [PATCH v33 5/5] trace-cmd [POC]: Add KVM timestamp synchronization plugin Tzvetomir Stoyanov (VMware)
2021-03-26 22:17 ` Steven Rostedt
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