From 991ae4eb36911fe9a99bef1c22b9578ceec3896a Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Sun, 27 Dec 2020 00:20:35 +0100 Subject: perf tools: Allow to enable/disable events via control file Adding new control events to enable/disable specific event. The interface string for control file are: 'enable ' 'disable ' when received the command, perf will scan the current evlist for and if found it's enabled/disabled. Example session: terminal 1: # mkfifo control ack perf.pipe # perf record --control=fifo:control,ack -D -1 --no-buffering -e 'sched:*' -o - > perf.pipe terminal 2: # cat perf.pipe | perf --no-pager script -i - terminal 1: Events disabled NOTE Above message will show only after read side of the pipe ('>') is started on 'terminal 2'. The 'terminal 1's bash does not execute perf before that, hence the delyaed perf record message. terminal 3: # echo 'enable sched:sched_process_fork' > control terminal 1: event sched:sched_process_fork enabled terminal 2: bash 33349 [034] 149587.674295: sched:sched_process_fork: comm=bash pid=33349 child_comm=bash child_pid=34056 bash 33349 [034] 149588.239521: sched:sched_process_fork: comm=bash pid=33349 child_comm=bash child_pid=34057 terminal 3: # echo 'enable sched:sched_wakeup_new' > control terminal 1: event sched:sched_wakeup_new enabled terminal 2: bash 33349 [034] 149632.228023: sched:sched_process_fork: comm=bash pid=33349 child_comm=bash child_pid=34059 bash 33349 [034] 149632.228050: sched:sched_wakeup_new: bash:34059 [120] success=1 CPU:036 bash 33349 [034] 149633.950005: sched:sched_process_fork: comm=bash pid=33349 child_comm=bash child_pid=34060 bash 33349 [034] 149633.950030: sched:sched_wakeup_new: bash:34060 [120] success=1 CPU:036 Committer testing: If I use 'sched:*' and then enable all events, I can't get 'perf record' to react to further commands, so I tested it with: [root@five ~]# perf record --control=fifo:control,ack -D -1 --no-buffering -e 'sched:sched_process_*' -o - > perf.pipe Events disabled Events enabled Events disabled And then it works as expected, so we need to fix this pre-existing problem. Another issue, we need to check if a event is already enabled or disabled and change the message to be clearer, i.e.: [root@five ~]# perf record --control=fifo:control,ack -D -1 --no-buffering -e 'sched:sched_process_*' -o - > perf.pipe Events disabled If we receive a 'disable' command, then it should say: [root@five ~]# perf record --control=fifo:control,ack -D -1 --no-buffering -e 'sched:sched_process_*' -o - > perf.pipe Events disabled Events already disabled Signed-off-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Acked-by: Namhyung Kim Cc: Alexander Shishkin Cc: Alexei Budankov Cc: Ian Rogers Cc: Mark Rutland Cc: Michael Petlan Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20201226232038.390883-2-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-record.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'tools/perf/builtin-record.c') diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 7704c33bfe31..71061a9af1c2 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -1938,18 +1938,14 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) if (evlist__ctlfd_process(rec->evlist, &cmd) > 0) { switch (cmd) { - case EVLIST_CTL_CMD_ENABLE: - pr_info(EVLIST_ENABLED_MSG); - break; - case EVLIST_CTL_CMD_DISABLE: - pr_info(EVLIST_DISABLED_MSG); - break; case EVLIST_CTL_CMD_SNAPSHOT: hit_auxtrace_snapshot_trigger(rec); evlist__ctlfd_ack(rec->evlist); break; case EVLIST_CTL_CMD_ACK: case EVLIST_CTL_CMD_UNSUPPORTED: + case EVLIST_CTL_CMD_ENABLE: + case EVLIST_CTL_CMD_DISABLE: default: break; } -- cgit v1.2.3