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| author | Kan Liang <kan.liang@intel.com> | 2015-06-17 09:51:10 -0400 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-06-19 18:20:15 -0300 |
| commit | 930e6fcd2bcce9bcd9d4aa7e755678d33f3fe6f4 (patch) | |
| tree | 5f85d268437a01f2a2982be31c82cb00a81efd85 /tools/perf/util/session.c | |
| parent | c05676c06232e6459a6106ddf0d4e154ce6cd859 (diff) | |
| download | lwn-930e6fcd2bcce9bcd9d4aa7e755678d33f3fe6f4.tar.gz lwn-930e6fcd2bcce9bcd9d4aa7e755678d33f3fe6f4.zip | |
perf tools: Add time out to force stop proc map processing
System wide sampling like 'perf top' or 'perf record -a' read all
threads /proc/xxx/maps before sampling. If there are any threads which
generating a keeping growing huge maps, perf will do infinite loop
during synthesizing. Nothing will be sampled.
This patch fixes this issue by adding per-thread timeout to force stop
this kind of endless proc map processing.
PERF_RECORD_MISC_PROC_MAP_PARSE_TIME_OUT is introduced to indicate that
the mmap record are truncated by time out. User will get warning
notification when truncated mmap records are detected.
Reported-by: Ying Huang <ying.huang@intel.com>
Signed-off-by: Kan Liang <kan.liang@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ying Huang <ying.huang@intel.com>
Link: http://lkml.kernel.org/r/1434549071-25611-1-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/session.c')
| -rw-r--r-- | tools/perf/util/session.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index c371336d1eb2..2d882fd1f1b9 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -1064,6 +1064,8 @@ static int machines__deliver_event(struct machines *machines, case PERF_RECORD_MMAP: return tool->mmap(tool, event, sample, machine); case PERF_RECORD_MMAP2: + if (event->header.misc & PERF_RECORD_MISC_PROC_MAP_PARSE_TIMEOUT) + ++evlist->stats.nr_proc_map_timeout; return tool->mmap2(tool, event, sample, machine); case PERF_RECORD_COMM: return tool->comm(tool, event, sample, machine); @@ -1360,6 +1362,15 @@ static void perf_session__warn_about_errors(const struct perf_session *session) ui__warning("%u out of order events recorded.\n", oe->nr_unordered_events); events_stats__auxtrace_error_warn(stats); + + if (stats->nr_proc_map_timeout != 0) { + ui__warning("%d map information files for pre-existing threads were\n" + "not processed, if there are samples for addresses they\n" + "will not be resolved, you may find out which are these\n" + "threads by running with -v and redirecting the output\n" + "to a file.\n", + stats->nr_proc_map_timeout); + } } static int perf_session__flush_thread_stack(struct thread *thread, |