diff options
| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-04-27 13:16:24 (GMT) |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-04-27 13:29:07 (GMT) |
| commit | 4cb93446c587d56e2a54f4f83113daba2c0b6dee (patch) | |
| tree | a251b1d510831dc071eadbbbe3e38a85fe643365 /tools/perf/Documentation | |
| parent | c5dfd78eb79851e278b7973031b9ca363da87a7e (diff) | |
| download | linux-4cb93446c587d56e2a54f4f83113daba2c0b6dee.tar.xz | |
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')
| -rw-r--r-- | tools/perf/Documentation/perf-report.txt | 2 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-script.txt | 2 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-top.txt | 2 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-trace.txt | 2 |
4 files changed, 4 insertions, 4 deletions
diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt index 496d42c..ebaf849 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:: diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt index 4fc44c7..a856a10 100644 --- a/tools/perf/Documentation/perf-script.txt +++ b/tools/perf/Documentation/perf-script.txt @@ -267,7 +267,7 @@ include::itrace.txt[] 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. --ns:: Use 9 decimal places when displaying time (i.e. show the nanoseconds) diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt index 19f046f..91d638d 100644 --- a/tools/perf/Documentation/perf-top.txt +++ b/tools/perf/Documentation/perf-top.txt @@ -177,7 +177,7 @@ Default is to monitor all CPUS. between information loss and faster processing especially for workloads that can have a very long callchain stack. - Default: 127 + Default: /proc/sys/kernel/perf_event_max_stack when present, 127 otherwise. --ignore-callees=<regex>:: Ignore callees of the function(s) matching the given regex. diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt index c075c00..6afe201 100644 --- a/tools/perf/Documentation/perf-trace.txt +++ b/tools/perf/Documentation/perf-trace.txt @@ -143,7 +143,7 @@ the thread executes on the designated CPUs. Default is to monitor all CPUs. Implies '--call-graph dwarf' when --call-graph not present on the command line, on systems where DWARF unwinding was built in. - Default: 127 + Default: /proc/sys/kernel/perf_event_max_stack when present, 127 otherwise. --min-stack:: Set the stack depth limit when parsing the callchain, anything |