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| author | Adrian Hunter <adrian.hunter@intel.com> | 2014-07-22 15:17:10 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2014-07-23 16:12:59 +0200 |
| commit | deaff8b659cf4d34181c087b8cdf74f1eb17b02b (patch) | |
| tree | c8ea4c936701091f4bc8a238fe8cbbe5d6d560de /tools/perf/util/cloexec.c | |
| parent | perf tools: Fix incorrect fd error comparison (diff) | |
| download | linux-deaff8b659cf4d34181c087b8cdf74f1eb17b02b.tar.xz linux-deaff8b659cf4d34181c087b8cdf74f1eb17b02b.zip | |
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/util/cloexec.c')
| -rw-r--r-- | tools/perf/util/cloexec.c | 9 |
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, |