Messages in this thread | | | Date | Thu, 13 Sep 2012 14:23:22 -0600 | From | David Ahern <> | Subject | Re: [PATCH] perf, tools: Stop perf stat -p when profiled process exits v3 |
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On 9/13/12 9:58 AM, Andi Kleen wrote: > From: Andi Kleen <ak@linux.intel.com> > > When counting a process with perf stat -p check if the process died > and exit collection if yes. > > v2: Add more checks, handle non -p again. Handle /proc not there. > v3: Handle multi pid case. Fix non /proc error path > Signed-off-by: Andi Kleen <ak@linux.intel.com> > --- > tools/perf/builtin-stat.c | 14 +++++++++++++- > 1 files changed, 13 insertions(+), 1 deletions(-) > > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c > index 861f0ae..b5e7df2 100644 > --- a/tools/perf/builtin-stat.c > +++ b/tools/perf/builtin-stat.c > @@ -536,7 +536,19 @@ static int run_perf_stat(int argc __used, const char **argv) > if (WIFSIGNALED(status)) > psignal(WTERMSIG(status), argv[0]); > } else { > - while(!done) sleep(1); > + char piddir[40]; > + int check_proc = target.pid && > + access("/proc", X_OK) == 0 && > + !strchr(target.pid, ','); > + if (check_proc) > + snprintf(piddir, sizeof piddir, "/proc/%d", > + atoi(target.pid)); > + while(!done) { > + sleep(1); > + if (check_proc && access(piddir, X_OK) < 0 && > + errno == ENOENT) > + break; > + } > }
I still think this is the wrong approach. A more complete solution would monitor all of the targets given by the user. e.g.,
1. create a perf_target__parse_pid - all it needs to do is: struct strlist *slist = strlist__new(false, pid_str); and save that into the target struct. That line is currently done in thread_map.c, thread_map__new_by_pid_str() and thread_map__new_by_tid_str. Those functions can be altered to take the slist instead of the string.
2. create a perf_target__is_alive that runs through each entry in the slist (strlist__for_each(pos, slist)) and checks that it still exists. As long as 1 target is alive it returns true. If no pid or tid is specified it always returns true.
The is_alive function can be used by perf-top, perf-stat and perf-record to know that its target has died so it can stop monitoring.
David
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