From: Kan Liang <kan.li...@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.hu...@intel.com>
Signed-off-by: Kan Liang <kan.li...@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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