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| author |   Arnaldo Carvalho de Melo <acme@redhat.com> | 2017-07-03 17:01:41 -0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2017-07-04 11:42:21 -0300 |
| commit | 97365e81366f5ca16a9ce66cff4dd4c5b0d9f4db (patch) | |
| tree | 101c61971e64048cec59a6c1b32c38d87e06d78f /tools | |
| parent | Merge tag 'perf-urgent-for-mingo-4.12-20170626' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent (diff) | |
| download | wireguard-linux-97365e81366f5ca16a9ce66cff4dd4c5b0d9f4db.tar.xz wireguard-linux-97365e81366f5ca16a9ce66cff4dd4c5b0d9f4db.zip | |
perf evsel: Set attr.exclude_kernel when probing max attr.precise_ip
We should set attr.exclude_kernel when probing for attr.precise_ip
level, otherwise !CAP_SYS_ADMIN users will not default to skidless
samples in capable hardware.
The increase in the paranoid level in commit 0161028b7c8a ("perf/core:
Change the default paranoia level to 2") broke this, fix it by excluding
kernel samples when probing.
Before:
$ perf record usleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.018 MB perf.data (6 samples) ]
$ perf evlist -v
cycles:u: sample_freq: 4000, sample_type: IP|TID|TIME|PERIOD, exclude_kernel: 1
After:
$ perf record usleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.018 MB perf.data (8 samples) ]
$ perf evlist -v
cycles:ppp: sample_freq: 4000, sample_type: IP|TID|TIME|PERIOD, exclude_kernel: 1, precise_ip: 3
^^^^^^^^^^^^^
^^^^^^^^^^^^^
^^^^^^^^^^^^^
$
To further clarify: we always set .exclude_kernel when non !CAP_SYS_ADMIN
users profile, its just on the attr.precise_ip probing that we weren't doing
so, fix it.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 7f8d1ade1b19 ("perf tools: By default use the most precise "cycles" hw counter available")
Link: http://lkml.kernel.org/n/tip-t2qttwhbnua62o5gt75cueml@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/util/evsel.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index cda44b0e821c..91192415f38d 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -269,6 +269,7 @@ struct perf_evsel *perf_evsel__new_cycles(void) struct perf_event_attr attr = { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CPU_CYCLES, + .exclude_kernel = 1, }; struct perf_evsel *evsel; |