This patch is a simplification of the logic introduced as part of
commit 63914aca8f7e ('perf tools: Show better error message in case we fail to 
open counters due to EBUSY error'):
if EBUSY is reported by perf_event_open(), it will not be possible
to probe PERF_FLAG_FD_CLOEXEC, so it's safe to leave early.

It should be noted that -EBUSY errors are not really expected here
since commit 038fa0b9739d ('perf tools: Fix PERF_FLAG_FD_CLOEXEC flag probing 
event type open counters due to EBUSY error'):
the perf event type used now should be safe to use regarding -EBUSY
error.

Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: William Cohen <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Yann Droneaud <[email protected]>
---
 tools/perf/util/cloexec.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/cloexec.c b/tools/perf/util/cloexec.c
index 2babddaa2481..be226d293c91 100644
--- a/tools/perf/util/cloexec.c
+++ b/tools/perf/util/cloexec.c
@@ -56,7 +56,11 @@ static int perf_flag_probe(void)
                return 1;
        }
 
-       WARN_ONCE(err != EINVAL && err != EBUSY,
+       /* ignore busy errors */
+       if (err == EBUSY)
+               return -1;
+
+       WARN_ONCE(err != EINVAL,
                  "perf_event_open(..., PERF_FLAG_FD_CLOEXEC) failed with 
unexpected error %d (%s)\n",
                  err, strerror_r(err, sbuf, sizeof(sbuf)));
 
@@ -74,7 +78,7 @@ static int perf_flag_probe(void)
        if (fd >= 0)
                close(fd);
 
-       if (WARN_ONCE(fd < 0 && err != EBUSY,
+       if (WARN_ONCE(fd < 0,
                      "perf_event_open(..., 0) failed unexpectedly with error 
%d (%s)\n",
                      err, strerror_r(err, sbuf, sizeof(sbuf))))
                return -1;
-- 
2.4.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to