[tip:perf/core] perf tests: No need to set attr.sample_freq for tracking !PERF_RECORD_SAMPLE

From: tip-bot for Arnaldo Carvalho de Melo
Date: Sat Jan 09 2016 - 11:35:08 EST


Commit-ID: 239849dde350c9f7356974ca4f62171f50a2c86e
Gitweb: http://git.kernel.org/tip/239849dde350c9f7356974ca4f62171f50a2c86e
Author: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate: Thu, 7 Jan 2016 16:51:58 -0300
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Thu, 7 Jan 2016 16:51:58 -0300

perf tests: No need to set attr.sample_freq for tracking !PERF_RECORD_SAMPLE

We were asking for a 4kHz sample_freq, making the test fail needlessly
when the system reduced /proc/sys/kernel/perf_event_max_sample_rate
below that.

Before:

# perf test -vv dummy
23: Test using a dummy software event to keep tracking :
--- start ---
test child forked, pid 32421
------------------------------------------------------------
perf_event_attr:
type 1
size 112
config 0x9
{ sample_period, sample_freq } 4000
sample_type IP|TID|ID|PERIOD
<SNIP>
sys_perf_event_open failed, error -22
Unable to open dummy and cycles event
test child finished with -2
---- end ----
Test using a dummy software event to keep tracking: Skip
#
[root@zoo ~]# cat /proc/sys/kernel/perf_event_max_sample_rate
1000

After:

[root@zoo ~]# perf test dummy
23: Test using a dummy software event to keep tracking : Ok

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-487iquegrs2379e5n0pi0tcp@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/tests/keep-tracking.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/tools/perf/tests/keep-tracking.c b/tools/perf/tests/keep-tracking.c
index a337a6d..6158132 100644
--- a/tools/perf/tests/keep-tracking.c
+++ b/tools/perf/tests/keep-tracking.c
@@ -55,7 +55,6 @@ int test__keep_tracking(int subtest __maybe_unused)
.mmap_pages = UINT_MAX,
.user_freq = UINT_MAX,
.user_interval = ULLONG_MAX,
- .freq = 4000,
.target = {
.uses_mmap = true,
},