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| author |   Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-04-27 10:16:24 -0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-04-27 10:29:07 -0300 |
| commit | 4cb93446c587d56e2a54f4f83113daba2c0b6dee (patch) | |
| tree | a251b1d510831dc071eadbbbe3e38a85fe643365 /tools/perf/Documentation/perf-report.txt | |
| parent | perf core: Allow setting up max frame stack depth via sysctl (diff) | |
| download | linux-dev-4cb93446c587d56e2a54f4f83113daba2c0b6dee.tar.xz linux-dev-4cb93446c587d56e2a54f4f83113daba2c0b6dee.zip | |
perf tools: Set the maximum allowed stack from /proc/sys/kernel/perf_event_max_stack
There is an upper limit to what tooling considers a valid callchain,
and it was tied to the hardcoded value in the kernel,
PERF_MAX_STACK_DEPTH (127), now that this can be tuned via a sysctl,
make it read it and use that as the upper limit, falling back to
PERF_MAX_STACK_DEPTH for kernels where this sysctl isn't present.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@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-yjqsd30nnkogvj5oyx9ghir9@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation/perf-report.txt')
| -rw-r--r-- | tools/perf/Documentation/perf-report.txt | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt index 496d42cdf02b..ebaf849e30ef 100644 --- a/tools/perf/Documentation/perf-report.txt +++ b/tools/perf/Documentation/perf-report.txt @@ -248,7 +248,7 @@ OPTIONS Note that when using the --itrace option the synthesized callchain size will override this value if the synthesized callchain size is bigger. - Default: 127 + Default: /proc/sys/kernel/perf_event_max_stack when present, 127 otherwise. -G:: --inverted:: |