From: Alexey Budankov <alexey.budankov@linux.intel.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Andi Kleen <ak@linux.intel.com>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: [PATCH v12 05/15] perf evlist: implement control command handling functions
Date: Fri, 17 Jul 2020 10:01:33 +0300 [thread overview]
Message-ID: <62518ceb-1cc9-2aba-593b-55408d07c1bf@linux.intel.com> (raw)
In-Reply-To: <8d91c3a0-3db4-0a7a-ae13-299adb444bd6@linux.intel.com>
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>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/util/evlist.c | 140 +++++++++++++++++++++++++++++++++++++++
tools/perf/util/evlist.h | 18 +++++
2 files changed, 158 insertions(+)
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 36eb50aba1f5..fe900d82815c 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1714,3 +1714,143 @@ 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,
+ fdarray_flag__nonfilterable);
+ 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;
+}
+
+bool evlist__ctlfd_initialized(struct evlist *evlist)
+{
+ return evlist->ctl_fd.pos >= 0;
+}
+
+int evlist__finalize_ctlfd(struct evlist *evlist)
+{
+ struct pollfd *entries = evlist->core.pollfd.entries;
+
+ if (!evlist__ctlfd_initialized(evlist))
+ 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);
+ 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,
+ (sizeof(EVLIST_CTL_CMD_ENABLE_TAG)-1))) {
+ *cmd = EVLIST_CTL_CMD_ENABLE;
+ } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG,
+ (sizeof(EVLIST_CTL_CMD_DISABLE_TAG)-1))) {
+ *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 (!evlist__ctlfd_initialized(evlist) || !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 fe1fe40e044b..cc628798734d 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -359,4 +359,22 @@ 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);
+bool evlist__ctlfd_initialized(struct evlist *evlist);
+int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd);
+
#endif /* __PERF_EVLIST_H */
--
2.24.1
next prev parent reply other threads:[~2020-07-17 7:01 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-17 6:45 [PATCH v12 00/15] perf: support enable and disable commands in stat and record modes Alexey Budankov
2020-07-17 6:59 ` [PATCH v12 01/15] tools/libperf: avoid internal moving of fdarray fds Alexey Budankov
2020-07-21 12:40 ` Arnaldo Carvalho de Melo
2020-07-17 6:59 ` [PATCH v12 02/15] tools/libperf: add flags to fdarray fds objects Alexey Budankov
2020-07-21 12:53 ` Arnaldo Carvalho de Melo
2020-07-17 7:00 ` [PATCH v12 03/15] tools/libperf: avoid counting of nonfilterable fdarray fds Alexey Budankov
2020-07-21 19:59 ` Arnaldo Carvalho de Melo
2020-07-17 7:00 ` [PATCH v12 04/15] perf evlist: introduce control file descriptors Alexey Budankov
2020-07-17 7:01 ` Alexey Budankov [this message]
2020-07-22 12:27 ` [PATCH v12 05/15] perf evlist: implement control command handling functions Arnaldo Carvalho de Melo
2020-07-22 12:34 ` Arnaldo Carvalho de Melo
2020-07-22 12:45 ` Alexey Budankov
2020-07-22 12:41 ` Arnaldo Carvalho de Melo
2020-07-17 7:02 ` [PATCH v12 06/15] perf stat: factor out body of event handling loop for system wide Alexey Budankov
2020-07-17 7:02 ` [PATCH v12 07/15] perf stat: move target check to loop control statement Alexey Budankov
2020-07-17 7:03 ` [PATCH v12 08/15] perf stat: factor out body of event handling loop for fork case Alexey Budankov
2020-07-17 7:04 ` [PATCH v12 09/15] perf stat: factor out event handling loop into dispatch_events() Alexey Budankov
2020-07-17 7:04 ` [PATCH v12 10/15] perf stat: extend -D,--delay option with -1 value Alexey Budankov
2020-07-17 7:05 ` [PATCH v12 11/15] perf stat: implement control commands handling Alexey Budankov
2020-07-22 12:56 ` Arnaldo Carvalho de Melo
2020-07-22 13:18 ` Alexey Budankov
2020-07-17 7:05 ` [PATCH v12 12/15] perf stat: introduce --control fd:ctl-fd[,ack-fd] options Alexey Budankov
2020-07-17 7:07 ` [PATCH v12 13/15] perf record: extend -D,--delay option with -1 value Alexey Budankov
2020-07-17 7:07 ` [PATCH v12 14/15] perf record: implement control commands handling Alexey Budankov
2020-07-17 7:08 ` [PATCH v12 15/15] perf record: introduce --control fd:ctl-fd[,ack-fd] options Alexey Budankov
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