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authorArnaldo Carvalho de Melo <acme@redhat.com>2016-02-18 13:45:25 -0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2016-02-19 19:12:44 -0300
commit5243ba76a585a6481c4d7b931e7e3d98900cbdbe (patch)
treecd212c582287ec556885b1dacf56b9e5a4d694ec /tools/perf/tests
parent6880bbf96930ec6f8b40b5b93f21973f3297672a (diff)
downloadlinux-5243ba76a585a6481c4d7b931e7e3d98900cbdbe.tar.gz
perf test: Reduce the sample_freq for the 'object code reading' test
Using 4 kHz is not necessary and sometimes is more than what was auto-tuned: # dmesg | grep max_sample_rate | tail -2 [ 2499.144373] perf interrupt took too long (2501 > 2500), lowering kernel.perf_event_max_sample_rate to 50000 [ 3592.413606] perf interrupt took too long (5069 > 5000), lowering kernel.perf_event_max_sample_rate to 25000 Simulating a auto-tune of 2000 we make the test fail, as reported by Steven Noonan for one of his machines, so reduce it to 500 HZ, it is enough to get a good number of samples for this test: # perf test -v 21 2>&1 | grep '^Reading object code for memory address' | tee /tmp/out | tail -5 Reading object code for memory address: 0x479f40 Reading object code for memory address: 0x7f29b7eea80d Reading object code for memory address: 0x7f29b7eea80d Reading object code for memory address: 0x7f29b7eea800 Reading object code for memory address: 0xffffffff813b2f23 [root@jouet ~]# wc -l /tmp/out 40 /tmp/out [root@jouet ~]# For systems that auto-tune below that, the previous patches will tell the user what is happening so that he may either ignore the result of this test or bump /proc/sys/kernel/perf_event_max_sample_rate. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Steven Noonan <steven@uplinklabs.net> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-6kufyy1iprdfzrbtuqgxir70@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/tests')
-rw-r--r--tools/perf/tests/code-reading.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
index f84339cb7f95..afc9ad0a0515 100644
--- a/tools/perf/tests/code-reading.c
+++ b/tools/perf/tests/code-reading.c
@@ -439,7 +439,7 @@ static int do_test_code_reading(bool try_kcore)
.mmap_pages = UINT_MAX,
.user_freq = UINT_MAX,
.user_interval = ULLONG_MAX,
- .freq = 4000,
+ .freq = 500,
.target = {
.uses_mmap = true,
},