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perf tools: Add time out to force stop proc map processing

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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>
This commit is contained in:
Kan Liang
2015-06-17 09:51:10 -04:00
committed by Arnaldo Carvalho de Melo
parent c05676c062
commit 930e6fcd2b
4 changed files with 34 additions and 0 deletions
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11
tools/perf/util/session.c
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@@ -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,