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author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-04-27 23:51:45 +0300 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-04-28 15:58:58 +0300 |
commit | de46d5268c4ec5c5b473c96fbf56ece188a6ba85 (patch) | |
tree | ec43e9d2bc049dc14ca6906128e05b8c110389ec /tools/perf/util/evsel.c | |
parent | 1a71476e4f2693ed93523c80ff1e2d4a8634717c (diff) | |
download | linux-de46d5268c4ec5c5b473c96fbf56ece188a6ba85.tar.xz |
perf evsel: Handle ENOMEM for perf_event_max_stack + PERF_SAMPLE_CALLCHAIN
When the kernel allows tweaking perf_event_max_stack and the event being
setup has PERF_SAMPLE_CALLCHAIN in its perf_event_attr.sample_type, tell
the user that tweaking /proc/sys/kernel/perf_event_max_stack may solve
the problem.
Before:
# echo 32000 > /proc/sys/kernel/perf_event_max_stack
# perf record -g usleep 1
Error:
The sys_perf_event_open() syscall returned with 12 (Cannot allocate memory) for event (cycles:ppp).
/bin/dmesg may provide additional information.
No CONFIG_PERF_EVENTS=y kernel support configured?
#
After:
# echo 64000 > /proc/sys/kernel/perf_event_max_stack
# perf record -g usleep 1
Error:
Not enough memory to setup event with callchain.
Hint: Try tweaking /proc/sys/kernel/perf_event_max_stack
Hint: Current value: 64000
#
Suggested-by: David Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ebv0orelj1s1ye857vhb82ov@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/evsel.c')
-rw-r--r-- | tools/perf/util/evsel.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 334364e25bbe..9bed7f4419d8 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2325,6 +2325,14 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target, "Probably the maximum number of open file descriptors has been reached.\n" "Hint: Try again after reducing the number of events.\n" "Hint: Try increasing the limit with 'ulimit -n <limit>'"); + case ENOMEM: + if ((evsel->attr.sample_type & PERF_SAMPLE_CALLCHAIN) != 0 && + access("/proc/sys/kernel/perf_event_max_stack", F_OK) == 0) + return scnprintf(msg, size, + "Not enough memory to setup event with callchain.\n" + "Hint: Try tweaking /proc/sys/kernel/perf_event_max_stack\n" + "Hint: Current value: %d", sysctl_perf_event_max_stack); + break; case ENODEV: if (target->cpu_list) return scnprintf(msg, size, "%s", |