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gerrit-public.fairphone.software / kernel / msm-4.9 / ff6e722870ddca2808b5d46159e58904f8ededf1 / . / tools / perf / Documentation / perf-diff.txt
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Arnaldo Carvalho de Melo86a9eee2009-12-14 20:09:31 -0200[diff] [blame]1perf-diff(1)
Arnaldo Carvalho de Melo4778e0e2010-05-05 11:23:27 -0300[diff] [blame]2============
Arnaldo Carvalho de Melo86a9eee2009-12-14 20:09:31 -0200[diff] [blame]3
4NAME
5----
Ingo Molnard30531c2009-12-15 10:24:08 +0100[diff] [blame]6perf-diff - Read two perf.data files and display the differential profile
Arnaldo Carvalho de Melo86a9eee2009-12-14 20:09:31 -0200[diff] [blame]7
8SYNOPSIS
9--------
10[verse]
11'perf diff' [oldfile] [newfile]
12
13DESCRIPTION
14-----------
Ingo Molnard30531c2009-12-15 10:24:08 +0100[diff] [blame]15This command displays the performance difference amongst two perf.data files
Arnaldo Carvalho de Melo86a9eee2009-12-14 20:09:31 -0200[diff] [blame]16captured via perf record.
17
18If no parameters are passed it will assume perf.data.old and perf.data.
19
Jiri Olsa863e4512012-09-06 17:46:55 +0200[diff] [blame]20The differential profile is displayed only for events matching both
21specified perf.data files.
22
Arnaldo Carvalho de Melo86a9eee2009-12-14 20:09:31 -0200[diff] [blame]23OPTIONS
24-------
Shawn Bohrer5ea4f852010-11-30 19:57:12 -0600[diff] [blame]25-D::
26--dump-raw-trace::
27 Dump raw trace in ASCII.
28
29-m::
30--modules::
31 Load module symbols. WARNING: use only with -k and LIVE kernel
32
Arnaldo Carvalho de Meloc351c282009-12-16 13:49:27 -0200[diff] [blame]33-d::
34--dsos=::
35 Only consider symbols in these dsos. CSV that understands
36 file://filename entries.
37
38-C::
39--comms=::
40 Only consider symbols in these comms. CSV that understands
41 file://filename entries.
42
43-S::
44--symbols=::
45 Only consider these symbols. CSV that understands
46 file://filename entries.
47
48-s::
49--sort=::
50 Sort by key(s): pid, comm, dso, symbol.
51
52-t::
53--field-separator=::
54
55 Use a special separator character and don't pad with spaces, replacing
Shawn Bohrer5ea4f852010-11-30 19:57:12 -0600[diff] [blame]56 all occurrences of this separator in symbol names (and other output)
Arnaldo Carvalho de Meloc351c282009-12-16 13:49:27 -0200[diff] [blame]57 with a '.' character, that thus it's the only non valid separator.
58
Arnaldo Carvalho de Melo86a9eee2009-12-14 20:09:31 -0200[diff] [blame]59-v::
60--verbose::
Ingo Molnard30531c2009-12-15 10:24:08 +0100[diff] [blame]61 Be verbose, for instance, show the raw counts in addition to the
Arnaldo Carvalho de Melo86a9eee2009-12-14 20:09:31 -0200[diff] [blame]62 diff.
Arnaldo Carvalho de Melocdccc692009-12-15 11:01:22 -0200[diff] [blame]63
Shawn Bohrer5ea4f852010-11-30 19:57:12 -0600[diff] [blame]64-f::
65--force::
66 Don't complain, do it.
67
David Ahernec5761e2010-12-09 13:27:07 -0700[diff] [blame]68--symfs=<directory>::
69 Look for files with symbols relative to this directory.
Shawn Bohrer5ea4f852010-11-30 19:57:12 -0600[diff] [blame]70
Jiri Olsaa06d1432012-10-05 16:44:40 +0200[diff] [blame]71-b::
72--baseline-only::
73 Show only items with match in baseline.
74
Jiri Olsa7aaf6b32012-10-05 16:44:41 +0200[diff] [blame]75-c::
76--compute::
Jiri Olsa81d5f952012-10-05 16:44:43 +0200[diff] [blame]77 Differential computation selection - delta,ratio,wdiff (default is delta).
Jiri Olsa96c47f12012-10-05 16:44:42 +0200[diff] [blame]78 If '+' is specified as a first character, the output is sorted based
79 on the computation results.
Jiri Olsa7aaf6b32012-10-05 16:44:41 +0200[diff] [blame]80 See COMPARISON METHODS section for more info.
81
Jiri Olsa61949b22012-10-05 16:44:44 +0200[diff] [blame]82-p::
83--period::
84 Show period values for both compared hist entries.
85
Jiri Olsaed279da2012-10-05 16:44:45 +0200[diff] [blame]86-F::
87--formula::
88 Show formula for given computation.
89
Jiri Olsa7aaf6b32012-10-05 16:44:41 +0200[diff] [blame]90COMPARISON METHODS
91------------------
92delta
93~~~~~
94If specified the 'Delta' column is displayed with value 'd' computed as:
95
96 d = A->period_percent - B->period_percent
97
98with:
99 - A/B being matching hist entry from first/second file specified
100 (or perf.data/perf.data.old) respectively.
101
102 - period_percent being the % of the hist entry period value within
103 single data file
104
105ratio
106~~~~~
107If specified the 'Ratio' column is displayed with value 'r' computed as:
108
109 r = A->period / B->period
110
111with:
112 - A/B being matching hist entry from first/second file specified
113 (or perf.data/perf.data.old) respectively.
114
115 - period being the hist entry period value
116
Jiri Olsa81d5f952012-10-05 16:44:43 +0200[diff] [blame]117wdiff
118~~~~~
119If specified the 'Weighted diff' column is displayed with value 'd' computed as:
120
121 d = B->period * WEIGHT-A - A->period * WEIGHT-B
122
123 - A/B being matching hist entry from first/second file specified
124 (or perf.data/perf.data.old) respectively.
125
126 - period being the hist entry period value
127
128 - WEIGHT-A/WEIGHT-B being user suplied weights in the the '-c' option
129 behind ':' separator like '-c wdiff:1,2'.
Jiri Olsa7aaf6b32012-10-05 16:44:41 +0200[diff] [blame]130
Arnaldo Carvalho de Melo86a9eee2009-12-14 20:09:31 -0200[diff] [blame]131SEE ALSO
132--------
133linkperf:perf-record[1]