6 perf-diff - Read two perf.data files and display the differential profile
11 'perf diff' [oldfile] [newfile]
15 This command displays the performance difference amongst two perf.data files
16 captured via perf record.
18 If no parameters are passed it will assume perf.data.old and perf.data.
20 The differential profile is displayed only for events matching both
21 specified perf.data files.
27 Dump raw trace in ASCII.
31 Load module symbols. WARNING: use only with -k and LIVE kernel
35 Only consider symbols in these dsos. CSV that understands
36 file://filename entries.
40 Only consider symbols in these comms. CSV that understands
41 file://filename entries.
45 Only consider these symbols. CSV that understands
46 file://filename entries.
50 Sort by key(s): pid, comm, dso, symbol.
55 Use a special separator character and don't pad with spaces, replacing
56 all occurrences of this separator in symbol names (and other output)
57 with a '.' character, that thus it's the only non valid separator.
61 Be verbose, for instance, show the raw counts in addition to the
66 Don't complain, do it.
69 Look for files with symbols relative to this directory.
73 Show only items with match in baseline.
77 Differential computation selection - delta,ratio,wdiff (default is delta).
78 If '+' is specified as a first character, the output is sorted based
79 on the computation results.
80 See COMPARISON METHODS section for more info.
84 Show period values for both compared hist entries.
88 Show formula for given computation.
94 If specified the 'Delta' column is displayed with value 'd' computed as:
96 d = A->period_percent - B->period_percent
99 - A/B being matching hist entry from first/second file specified
100 (or perf.data/perf.data.old) respectively.
102 - period_percent being the % of the hist entry period value within
107 If specified the 'Ratio' column is displayed with value 'r' computed as:
109 r = A->period / B->period
112 - A/B being matching hist entry from first/second file specified
113 (or perf.data/perf.data.old) respectively.
115 - period being the hist entry period value
119 If specified the 'Weighted diff' column is displayed with value 'd' computed as:
121 d = B->period * WEIGHT-A - A->period * WEIGHT-B
123 - A/B being matching hist entry from first/second file specified
124 (or perf.data/perf.data.old) respectively.
126 - period being the hist entry period value
128 - WEIGHT-A/WEIGHT-B being user suplied weights in the the '-c' option
129 behind ':' separator like '-c wdiff:1,2'.
133 linkperf:perf-record[1]