linux/tools/perf/Documentation
Greg Price b21484f1a1 perf report/top: Add option to collapse undesired parts of call graph
For example, in an application with an expensive function implemented
with deeply nested recursive calls, the default call-graph presentation
is dominated by the different callchains within that function.  By
ignoring these callees, we can collect the callchains leading into the
function and compactly identify what to blame for expensive calls.

For example, in this report the callers of garbage_collect() are
scattered across the tree:

  $ perf report -d ruby 2>- | grep -m10 ^[^#]*[a-z]
      22.03%     ruby  [.] gc_mark
                 --- gc_mark
                    |--59.40%-- mark_keyvalue
                    |          st_foreach
                    |          gc_mark_children
                    |          |--99.75%-- rb_gc_mark
                    |          |          rb_vm_mark
                    |          |          gc_mark_children
                    |          |          gc_marks
                    |          |          |--99.00%-- garbage_collect

If we ignore the callees of garbage_collect(), its callers are coalesced:

  $ perf report --ignore-callees garbage_collect -d ruby 2>- | grep -m10 ^[^#]*[a-z]
      72.92%     ruby  [.] garbage_collect
                 --- garbage_collect
                     vm_xmalloc
                    |--47.08%-- ruby_xmalloc
                    |          st_insert2
                    |          rb_hash_aset
                    |          |--98.45%-- features_index_add
                    |          |          rb_provide_feature
                    |          |          rb_require_safe
                    |          |          vm_call_method

Signed-off-by: Greg Price <price@mit.edu>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130623031720.GW22203@biohazard-cafe.mit.edu
Link: http://lkml.kernel.org/r/20130708115746.GO22203@biohazard-cafe.mit.edu
Cc: Fengguang Wu <fengguang.wu@intel.com>
[ remove spaces at beginning of line, reported by Fengguang Wu ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-07-12 13:53:55 -03:00
..
android.txt perf tools: Add info about cross compiling for Android ARM 2012-10-31 12:17:49 -02:00
asciidoc.conf perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ 2009-06-06 20:33:43 +02:00
examples.txt perf record: Remove -f/--force option 2013-07-08 17:37:25 -03:00
jit-interface.txt perf symbols: Add description of JIT interface 2012-08-13 14:55:02 -03:00
Makefile perf tools: Fix output directory of Documentation/ 2013-07-08 17:31:49 -03:00
manpage-1.72.xsl perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ 2009-06-06 20:33:43 +02:00
manpage-base.xsl perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ 2009-06-06 20:33:43 +02:00
manpage-bold-literal.xsl perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ 2009-06-06 20:33:43 +02:00
manpage-normal.xsl perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ 2009-06-06 20:33:43 +02:00
manpage-suppress-sp.xsl perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ 2009-06-06 20:33:43 +02:00
perf-annotate.txt perf annotate: Add basic support to event group view 2013-03-15 13:06:05 -03:00
perf-archive.txt perf archive: Fix typo on Documentation 2013-05-28 16:23:55 +03:00
perf-bench.txt perf bench: Fix confused variable namings and descriptions in mem subsystem 2012-07-02 14:35:45 -03:00
perf-buildid-cache.txt perf buildid-cache: Add --update option 2013-02-14 14:59:27 -03:00
perf-buildid-list.txt perf report: Accept fifos as input file 2011-12-23 17:01:03 -02:00
perf-diff.txt perf diff: Remove displacement output option 2012-12-09 08:46:07 -03:00
perf-evlist.txt perf evlist: Add --group option 2013-01-31 13:07:49 -03:00
perf-help.txt perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ 2009-06-06 20:33:43 +02:00
perf-inject.txt perf inject: Merge sched_stat_* and sched_switch events 2012-10-26 11:22:25 -02:00
perf-kmem.txt perf report: Accept fifos as input file 2011-12-23 17:01:03 -02:00
perf-kvm.txt perf kvm: Events analysis tool 2012-09-21 12:51:22 -03:00
perf-list.txt perf list: List kernel supplied event aliases 2013-07-12 13:53:53 -03:00
perf-lock.txt perf lock: Document lock info subcommand 2012-01-30 18:30:48 -02:00
perf-mem.txt perf tools: Add new mem command for memory access profiling 2013-04-01 12:21:44 -03:00
perf-probe.txt perf probe: Detect probe target when m/x options are absent 2012-05-11 13:58:53 -03:00
perf-record.txt perf record: Remove -f/--force option 2013-07-08 17:37:25 -03:00
perf-report.txt perf report/top: Add option to collapse undesired parts of call graph 2013-07-12 13:53:55 -03:00
perf-sched.txt perf report: Accept fifos as input file 2011-12-23 17:01:03 -02:00
perf-script-perl.txt perf script perl/python: Fix libexec scripts path in Documentation 2012-08-20 09:30:36 -03:00
perf-script-python.txt perf script: Remove workqueue-stats script 2013-01-24 16:40:53 -03:00
perf-script.txt perf script: Add option resolving vmlinux path 2012-01-30 18:13:07 -02:00
perf-stat.txt perf stat: Add per-core aggregation 2013-03-25 16:13:26 -03:00
perf-test.txt perf test: Allow skipping tests 2013-01-24 16:40:53 -03:00
perf-timechart.txt perf report: Accept fifos as input file 2011-12-23 17:01:03 -02:00
perf-top.txt perf report/top: Add option to collapse undesired parts of call graph 2013-07-12 13:53:55 -03:00
perf-trace.txt perf trace: Use sched:sched_stat_runtime to provide a thread summary 2012-10-25 10:57:43 -02:00
perf.txt perf: Fix few typos + cosmetics 2010-01-13 17:39:44 +01:00
perfconfig.example perf annotate browser: Read perf config file for settings 2012-05-29 22:06:30 -03:00