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authorArnaldo Carvalho de Melo <acme@redhat.com>2017-07-03 17:01:41 -0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2017-07-04 11:42:21 -0300
commit97365e81366f5ca16a9ce66cff4dd4c5b0d9f4db (patch)
tree101c61971e64048cec59a6c1b32c38d87e06d78f /tools/perf
parente3c2c4fb524b548e58108a8820c0ac7787667584 (diff)
downloadlinux-97365e81366f5ca16a9ce66cff4dd4c5b0d9f4db.tar.bz2
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/perf')
-rw-r--r--tools/perf/util/evsel.c1
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;