diff options
| author | Adrian Hunter <adrian.hunter@intel.com> | 2020-09-01 12:37:57 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2020-09-04 20:38:15 +0300 |
| commit | d20aff1512f013fab79b8740427b7574569a9a2e (patch) | |
| tree | 43c5261c26024130049b82902d24a0972baca09d /tools/perf/util/evlist.c | |
| parent | a8fcbd269b4340c36dbf99b4453bcbfe128d93fb (diff) | |
| download | linux-d20aff1512f013fab79b8740427b7574569a9a2e.tar.xz | |
perf record: Add 'snapshot' control command
Add 'snapshot' control command to create an AUX area tracing snapshot
the same as if sending SIGUSR2. The advantage of the FIFO is that access
is governed by access to the FIFO.
Example:
$ mkfifo perf.control
$ mkfifo perf.ack
$ cat perf.ack &
[1] 15235
$ sudo ~/bin/perf record --control fifo:perf.control,perf.ack -S -e intel_pt//u -- sleep 60 &
[2] 15243
$ ps -e | grep perf
15244 pts/1 00:00:00 perf
$ kill -USR2 15244
bash: kill: (15244) - Operation not permitted
$ echo snapshot > perf.control
ack
$
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/20200901093758.32293-6-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/evlist.c')
| -rw-r--r-- | tools/perf/util/evlist.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 00593e5f2a9d..e72ff7e78dec 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -1887,13 +1887,17 @@ static int evlist__ctlfd_recv(struct evlist *evlist, enum evlist_ctl_cmd *cmd, } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG, (sizeof(EVLIST_CTL_CMD_DISABLE_TAG)-1))) { *cmd = EVLIST_CTL_CMD_DISABLE; + } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_SNAPSHOT_TAG, + (sizeof(EVLIST_CTL_CMD_SNAPSHOT_TAG)-1))) { + *cmd = EVLIST_CTL_CMD_SNAPSHOT; + pr_debug("is snapshot\n"); } } return bytes_read ? (int)bytes_read : err; } -static int evlist__ctlfd_ack(struct evlist *evlist) +int evlist__ctlfd_ack(struct evlist *evlist) { int err; @@ -1929,13 +1933,16 @@ int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd) case EVLIST_CTL_CMD_DISABLE: evlist__disable(evlist); break; + case EVLIST_CTL_CMD_SNAPSHOT: + 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)) + if (!(*cmd == EVLIST_CTL_CMD_ACK || *cmd == EVLIST_CTL_CMD_UNSUPPORTED || + *cmd == EVLIST_CTL_CMD_SNAPSHOT)) evlist__ctlfd_ack(evlist); } } |