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authorArnaldo Carvalho de Melo <acme@redhat.com>2016-04-27 17:51:45 -0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2016-04-28 09:58:58 -0300
commitde46d5268c4ec5c5b473c96fbf56ece188a6ba85 (patch)
treeec43e9d2bc049dc14ca6906128e05b8c110389ec /tools
parent1a71476e4f2693ed93523c80ff1e2d4a8634717c (diff)
downloadlinux-de46d5268c4ec5c5b473c96fbf56ece188a6ba85.tar.bz2
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')
-rw-r--r--tools/perf/util/evsel.c8
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",