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authorKan Liang <kan.liang@intel.com>2015-06-17 15:51:10 +0200
committerArnaldo Carvalho de Melo <acme@redhat.com>2015-06-19 23:20:15 +0200
commit930e6fcd2bcce9bcd9d4aa7e755678d33f3fe6f4 (patch)
tree5f85d268437a01f2a2982be31c82cb00a81efd85 /tools/perf/util/session.c
parentperf report: Fix sort__sym_cmp to also compare end of symbol (diff)
downloadlinux-930e6fcd2bcce9bcd9d4aa7e755678d33f3fe6f4.tar.xz
linux-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.c11
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,