Messages in this thread Patch in this message | | | From | kan.liang@intel ... | Subject | [PATCH 1/1] perf,tools: add time out to force stop endless mmap processing | Date | Wed, 10 Jun 2015 03:46:04 -0400 |
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From: Kan Liang <kan.liang@intel.com>
perf top reads all threads' /proc/xxx/maps. If there is any threads which generating a keeping growing huge /proc/xxx/maps, perf will do infinite loop in perf_event__synthesize_mmap_events. This patch fixes this issue by adding a time out to force stop this kind of endless mmap processing.
Reported-by: Huang, Ying <ying.huang@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> --- tools/perf/util/event.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c index 793b150..0df7f2a9 100644 --- a/tools/perf/util/event.c +++ b/tools/perf/util/event.c @@ -213,6 +213,8 @@ static int perf_event__synthesize_fork(struct perf_tool *tool, return 0; } +#define MMAP_TIMEOUT (50 * 1000000ULL) + int perf_event__synthesize_mmap_events(struct perf_tool *tool, union perf_event *event, pid_t pid, pid_t tgid, @@ -222,6 +224,7 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool, { char filename[PATH_MAX]; FILE *fp; + unsigned long long t; int rc = 0; if (machine__is_default_guest(machine)) @@ -240,6 +243,7 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool, } event->header.type = PERF_RECORD_MMAP2; + t = rdclock(); while (1) { char bf[BUFSIZ]; @@ -250,7 +254,8 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool, size_t size; ssize_t n; - if (fgets(bf, sizeof(bf), fp) == NULL) + if ((fgets(bf, sizeof(bf), fp) == NULL) || + ((rdclock() - t) > MMAP_TIMEOUT)) break; /* ensure null termination since stack will be reused. */ -- 1.8.3.1
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