Adding new control events to enable/disable specific event.
The interface string for control file are:
'enable <EVENT NAME>'
'disable <EVENT NAME>'
when received the command, perf will scan the current evlist
for <EVENT NAME> 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 <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201226232038.390883-2-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Listen on ctl-fd descriptor for command to control measurement.
Available commands:
- 'enable' : enable events
- 'disable' : disable events
- 'snapshot': AUX area tracing snapshot).
+ 'enable' : enable events
+ 'disable' : disable events
+ 'enable name' : enable event 'name'
+ 'disable name' : disable event 'name'
+ 'snapshot' : AUX area tracing snapshot).
Measurements can be started with events disabled using --delay=-1 option. Optionally
send control command completion ('ack\n') to ack-fd descriptor to synchronize with the
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;
}
if (evlist__ctlfd_process(evlist, &cmd) > 0) {
switch (cmd) {
case EVLIST_CTL_CMD_ENABLE:
- pr_info(EVLIST_ENABLED_MSG);
if (interval)
process_interval();
break;
case EVLIST_CTL_CMD_DISABLE:
if (interval)
process_interval();
- pr_info(EVLIST_DISABLED_MSG);
break;
case EVLIST_CTL_CMD_SNAPSHOT:
case EVLIST_CTL_CMD_ACK:
return err;
}
+static int get_cmd_arg(char *cmd_data, size_t cmd_size, char **arg)
+{
+ char *data = cmd_data + cmd_size;
+
+ /* no argument */
+ if (!*data)
+ return 0;
+
+ /* there's argument */
+ if (*data == ' ') {
+ *arg = data + 1;
+ return 1;
+ }
+
+ /* malformed */
+ return -1;
+}
+
+static int evlist__ctlfd_enable(struct evlist *evlist, char *cmd_data, bool enable)
+{
+ struct evsel *evsel;
+ char *name;
+ int err;
+
+ err = get_cmd_arg(cmd_data,
+ enable ? sizeof(EVLIST_CTL_CMD_ENABLE_TAG) - 1 :
+ sizeof(EVLIST_CTL_CMD_DISABLE_TAG) - 1,
+ &name);
+ if (err < 0) {
+ pr_info("failed: wrong command\n");
+ return -1;
+ }
+
+ if (err) {
+ evsel = evlist__find_evsel_by_str(evlist, name);
+ if (evsel) {
+ if (enable)
+ evlist__enable_evsel(evlist, name);
+ else
+ evlist__disable_evsel(evlist, name);
+ pr_info("Event %s %s\n", evsel->name,
+ enable ? "enabled" : "disabled");
+ } else {
+ pr_info("failed: can't find '%s' event\n", name);
+ }
+ } else {
+ if (enable) {
+ evlist__enable(evlist);
+ pr_info(EVLIST_ENABLED_MSG);
+ } else {
+ evlist__disable(evlist);
+ pr_info(EVLIST_DISABLED_MSG);
+ }
+ }
+
+ return 0;
+}
+
int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd)
{
int err = 0;
if (err > 0) {
switch (*cmd) {
case EVLIST_CTL_CMD_ENABLE:
- evlist__enable(evlist);
- break;
case EVLIST_CTL_CMD_DISABLE:
- evlist__disable(evlist);
+ err = evlist__ctlfd_enable(evlist, cmd_data,
+ *cmd == EVLIST_CTL_CMD_ENABLE);
break;
case EVLIST_CTL_CMD_SNAPSHOT:
break;
projects / linux-2.6-microblaze.git / commitdiff