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| author | Kan Liang <kan.liang@intel.com> | 2015-08-11 13:30:49 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-08-12 19:20:28 +0300 |
| commit | 9e207ddfa20781e56465ce9a537f0a377c9d34fb (patch) | |
| tree | 8eea5617ff1c5e997a591ef8733aae16e1668aee /tools/perf/Documentation/perf-report.txt | |
| parent | f9db0d0f1b2cf030083c83d3ed3a4bbae6bdc8b7 (diff) | |
| download | linux-9e207ddfa20781e56465ce9a537f0a377c9d34fb.tar.xz | |
perf report: Show call graph from reference events
Introduce --show-ref-call-graph for perf report to print reference
callgraph for no callgraph event.
Here is an example.
perf report --show-ref-call-graph --stdio
# To display the perf.data header info, please use
--header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 5 of event 'cpu/cpu-cycles,call-graph=fp/'
# Event count (approx.): 144985
#
# Children Self Command Shared Object Symbol
# ........ ........ ....... ................ ........................................
#
72.30% 0.00% sleep [kernel.vmlinux] [k] entry_SYSCALL_64_fastpath
|
---entry_SYSCALL_64_fastpath
|
|--22.62%-- __GI___libc_nanosleep
--77.38%-- [...]
......
# Samples: 6 of event 'cpu/instructions,call-graph=no/', show reference callgraph
# Event count (approx.): 172780
#
# Children Self Command Shared Object Symbol
# ........ ........ ....... ................ ........................................
#
73.16% 0.00% sleep [kernel.vmlinux] [k] entry_SYSCALL_64_fastpath
|
---entry_SYSCALL_64_fastpath
|
|--31.44%-- __GI___libc_nanosleep
--68.56%-- [...]
Signed-off-by: Kan Liang <kan.liang@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1439289050-40510-3-git-send-email-kan.liang@intel.com
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 | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt index 7b07d19e2d54..a18ba757a0ed 100644 --- a/tools/perf/Documentation/perf-report.txt +++ b/tools/perf/Documentation/perf-report.txt @@ -359,6 +359,17 @@ OPTIONS --full-source-path:: Show the full path for source files for srcline output. +--show-ref-call-graph:: + When multiple events are sampled, it may not be needed to collect + callgraphs for all of them. The sample sites are usually nearby, + and it's enough to collect the callgraphs on a reference event. + So user can use "call-graph=no" event modifier to disable callgraph + for other events to reduce the overhead. + However, perf report cannot show callgraphs for the event which + disable the callgraph. + This option extends the perf report to show reference callgraphs, + which collected by reference event, in no callgraph event. + include::callchain-overhead-calculation.txt[] SEE ALSO |