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authorAdrian Hunter <adrian.hunter@intel.com>2014-07-22 16:17:10 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2014-07-23 11:12:59 -0300
commitdeaff8b659cf4d34181c087b8cdf74f1eb17b02b (patch)
treec8ea4c936701091f4bc8a238fe8cbbe5d6d560de /tools/perf
parenta6f6ae99f12e8154d5cde6e8366fc228f68d6ae5 (diff)
perf tools: Fix jump label always changing during tracing
Intel PT decoding walks the object code to reconstruct the trace. A jump label change during tracing causes decoding errors. The "Enable close-on-exec flag on perf file descriptor" patch caused there to be always a jump label change. It was found that using a per-cpu context instead of a per-thread context for the probe of the close-on-exec feature, made the problem go away. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1406035081-14301-2-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf')
-rw-r--r--tools/perf/util/cloexec.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/tools/perf/util/cloexec.c b/tools/perf/util/cloexec.c
index c5d05ec17220..6a37be53a5d2 100644
--- a/tools/perf/util/cloexec.c
+++ b/tools/perf/util/cloexec.c
@@ -1,3 +1,4 @@
+#include <sched.h>
#include "util.h"
#include "../perf.h"
#include "cloexec.h"
@@ -14,9 +15,13 @@ static int perf_flag_probe(void)
};
int fd;
int err;
+ int cpu = sched_getcpu();
+
+ if (cpu < 0)
+ cpu = 0;
/* check cloexec flag */
- fd = sys_perf_event_open(&attr, 0, -1, -1,
+ fd = sys_perf_event_open(&attr, -1, cpu, -1,
PERF_FLAG_FD_CLOEXEC);
err = errno;
@@ -30,7 +35,7 @@ static int perf_flag_probe(void)
err, strerror(err));
/* not supported, confirm error related to PERF_FLAG_FD_CLOEXEC */
- fd = sys_perf_event_open(&attr, 0, -1, -1, 0);
+ fd = sys_perf_event_open(&attr, -1, cpu, -1, 0);
err = errno;
if (WARN_ONCE(fd < 0,