From b21484f1a1f300d422cfe5d4f8f50015e22cea24 Mon Sep 17 00:00:00 2001
From: Greg Price <price@MIT.EDU>
Date: Thu, 6 Dec 2012 21:48:05 -0800
Subject: 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>
---
 tools/perf/util/machine.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

(limited to 'tools/perf/util/machine.h')

diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
index e49ba01b7937..5bb6244194d5 100644
--- a/tools/perf/util/machine.h
+++ b/tools/perf/util/machine.h
@@ -5,6 +5,7 @@
 #include <linux/rbtree.h>
 #include "map.h"
 
+struct addr_location;
 struct branch_stack;
 struct perf_evsel;
 struct perf_sample;
@@ -83,7 +84,8 @@ int machine__resolve_callchain(struct machine *machine,
 			       struct perf_evsel *evsel,
 			       struct thread *thread,
 			       struct perf_sample *sample,
-			       struct symbol **parent);
+			       struct symbol **parent,
+			       struct addr_location *root_al);
 
 /*
  * Default guest kernel is defined by parameter --guestkallsyms
-- 
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