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authorAnton Blanchard <anton@samba.org>2011-07-04 21:57:50 +1000
committerIngo Molnar <mingo@elte.hu>2011-07-05 10:44:44 +0200
commit5d67be97f8903d05ce53597fb5f3bc25a45e8026 (patch)
tree5ce8c2407d50570d7fee79b9c7f24e8eb89384b4 /tools/perf/Documentation/perf-annotate.txt
parent9f8b6a6cf0ee78de87ebe1e87f54bec1c1741ef7 (diff)
downloadvexpress-lsk-5d67be97f8903d05ce53597fb5f3bc25a45e8026.tar.gz
perf report/annotate/script: Add option to specify a CPU range
Add an option to perf report/annotate/script to specify which CPUs to operate on. This enables us to take a single system wide profile and analyse each CPU (or group of CPUs) in isolation. This was useful when profiling a multiprocess workload where the bottleneck was on one CPU but this was hidden in the overall profile. Per process and per thread breakdowns didn't help because multiple processes were running on each CPU and no single process consumed an entire CPU. The patch converts the list of CPUs returned by cpu_map__new into a bitmap for fast lookup. I wanted to use -C to be consistent with perf top/record/stat, but unfortunately perf report already uses -C <comms>. v2: Incorporate suggestions from David Ahern: - Added -c to perf script - Check that SAMPLE_CPU is set when -c is used - Update documentation v3: Create perf_session__cpu_bitmap() Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: David Ahern <dsahern@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Link: http://lkml.kernel.org/r/20110704215750.11647eb9@kryten Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'tools/perf/Documentation/perf-annotate.txt')
-rw-r--r--tools/perf/Documentation/perf-annotate.txt6
1 files changed, 6 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-annotate.txt b/tools/perf/Documentation/perf-annotate.txt
index 6f5a498608b..85c5f026930 100644
--- a/tools/perf/Documentation/perf-annotate.txt
+++ b/tools/perf/Documentation/perf-annotate.txt
@@ -66,6 +66,12 @@ OPTIONS
used. This interfaces starts by centering on the line with more
samples, TAB/UNTAB cycles through the lines with more samples.
+-c::
+--cpu:: Only report samples for the list of CPUs provided. Multiple CPUs can
+ be provided as a comma-separated list with no space: 0,1. Ranges of
+ CPUs are specified with -: 0-2. Default is to report samples on all
+ CPUs.
+
SEE ALSO
--------
linkperf:perf-record[1], linkperf:perf-report[1]