perf record: Fix fast task-exit race
Recording with -a (or with -p) can race with tasks going away:
couldn't open /proc/8440/maps
Causing an early exit() and no recording done.
Do not abort the recording session - instead just skip that task.
Also, only print the warnings under -v.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index a177a59..e1dfef2 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -202,8 +202,12 @@
fd = open(filename, O_RDONLY);
if (fd < 0) {
- fprintf(stderr, "couldn't open %s\n", filename);
- exit(EXIT_FAILURE);
+ /*
+ * We raced with a task exiting - just return:
+ */
+ if (verbose)
+ fprintf(stderr, "couldn't open %s\n", filename);
+ return;
}
if (read(fd, bf, sizeof(bf)) < 0) {
fprintf(stderr, "couldn't read %s\n", filename);
@@ -273,8 +277,12 @@
fp = fopen(filename, "r");
if (fp == NULL) {
- fprintf(stderr, "couldn't open %s\n", filename);
- exit(EXIT_FAILURE);
+ /*
+ * We raced with a task exiting - just return:
+ */
+ if (verbose)
+ fprintf(stderr, "couldn't open %s\n", filename);
+ return;
}
while (1) {
char bf[BUFSIZ], *pbf = bf;