* [tip:perf/core] perf evlist: Monitor POLLERR and POLLHUP events too
@ 2014-09-26 9:19 tip-bot for Arnaldo Carvalho de Melo
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From: tip-bot for Arnaldo Carvalho de Melo @ 2014-09-26 9:19 UTC (permalink / raw)
To: linux-tip-commits
Cc: eranian, acme, mingo, jolsa, peterz, efault, jolsa, fweisbec,
dsahern, tglx, dzickus, hpa, paulus, linux-kernel, namhyung,
adrian.hunter
Commit-ID: 8179672c2f7b9c41a7ef3e8c907d214fa92ed614
Gitweb: http://git.kernel.org/tip/8179672c2f7b9c41a7ef3e8c907d214fa92ed614
Author: Arnaldo Carvalho de Melo <acme@redhat.com>
AuthorDate: Wed, 13 Aug 2014 11:26:21 -0300
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Thu, 25 Sep 2014 16:46:54 -0300
perf evlist: Monitor POLLERR and POLLHUP events too
We want to know when the fd went away, like when a monitored thread
exits.
If we do not monitor such events, then the tools will wait forever on
events from a vanished thread, like when running:
$ sleep 5s &
$ perf record -p `pidof sleep`
This builds upon the kernel patch by Jiri Olsa that actually makes a
poll on those file descriptors to return POLLHUP.
It is also needed to change the tools to use
perf_evlist__filter_pollfd() to check if there are remainings fds to
monitor or if all are gone, in which case they will exit the
poll/mmap/read loop.
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-a4fslwspov0bs69nj825hqpq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/evlist.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 023bc38..502cd11 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -424,7 +424,7 @@ void perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd)
{
fcntl(fd, F_SETFL, O_NONBLOCK);
evlist->pollfd[evlist->nr_fds].fd = fd;
- evlist->pollfd[evlist->nr_fds].events = POLLIN;
+ evlist->pollfd[evlist->nr_fds].events = POLLIN | POLLERR | POLLHUP;
evlist->nr_fds++;
}
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