perf/Documentation/perf-diff.txt

1 perf-diff(1)
5 ----
6 perf-diff - Read perf.data files and display the differential profile
9 --------
14 -----------
29 -------
30 -D::
31 --dump-raw-trace::
34 --kallsyms=<file>::
37 -m::
38 --modules::
39         Load module symbols. WARNING: use only with -k and LIVE kernel
41 -d::
42 --dsos=::
45 	of the Baseline/Delta column.  See --percentage for more info.
47 -C::
48 --comms=::
51 	of the Baseline/Delta column.  See --percentage for more info.
53 -S::
54 --symbols=::
57 	of the Baseline/Delta column.  See --percentage for more info.
59 -s::
60 --sort=::
62 	Please see description of --sort in the perf-report man page.
64 -t::
65 --field-separator=::
71 -v::
72 --verbose::
76 -q::
77 --quiet::
78 	Do not show any warnings or messages.  (Suppress -v)
80 -f::
81 --force::
84 --symfs=<directory>::
87 -b::
88 --baseline-only::
91 -c::
92 --compute::
93         Differential computation selection - delta, ratio, wdiff, cycles,
94         delta-abs (default is delta-abs).  Default can be changed using
98 --cycles-hist::
101 	not. This option should be used with '-c cycles'.
103 -p::
104 --period::
107 -F::
108 --formula::
111 -o::
112 --order::
119 --percentage::
121 	Filters can be applied by --comms, --dsos and/or --symbols options.
127 --time::
130 	or 'a%-b%,c%-%d,...'.
136 	  perf diff --time 10%/2
140 	  perf diff --time 0%-10%
144 	  perf diff --time 10%/1,10%/2
148 	  perf diff --time 0%-10%,30%-40%
156 	to be quoted e.g. --time "1234.567,1234.789 1235,"
162 	  perf script -i perf.data.old
165 	  perf script -i perf.data
168 	  perf diff --time 3946.361400,:3971.150589,
174 --cpu:: Only diff samples for the list of CPUs provided. Multiple CPUs can
175 	be provided as a comma-separated list with no space: 0,1. Ranges of
176 	CPUs are specified with -: 0-2. Default is to report samples on all
179 --pid=::
182 --tid=::
185 --stream::
190 ----------
196 All samples from non-baseline perf.data files, that do not match any
201 - file A with samples f1, f2, f3, f4,    f6
202 - file B with samples     f2,     f4, f5
203 - file C with samples f1, f2,         f5
206   x - computation takes place for pair
207   b - baseline sample percentage
209 - perf diff A B C
212   ---------------------------------------
220 - perf diff B A C
223   ---------------------------------------
231 - perf diff C B A
234   ---------------------------------------
243 ------------------
248   d = A->period_percent - B->period_percent
251   - A/B being matching hist entry from data/baseline file specified
254   - period_percent being the % of the hist entry period value within
257   - with filtering by -C, -d and/or -S, period_percent might be changed
258     relative to how entries are filtered.  Use --percentage=absolute to
261 delta-abs
269   r = A->period / B->period
272   - A/B being matching hist entry from data/baseline file specified
275   - period being the hist entry period value
277 wdiff:WEIGHT-B,WEIGHT-A
281    d = B->period * WEIGHT-A - A->period * WEIGHT-B
283   - A/B being matching hist entry from data/baseline file specified
286   - period being the hist entry period value
288   - WEIGHT-A/WEIGHT-B being user supplied weights in the the '-c' option
289     behind ':' separator like '-c wdiff:1,2'.
290     - WEIGHT-A being the weight of the data file
291     - WEIGHT-B being the weight of the baseline data file
295 If specified the '[Program Block Range] Cycles Diff' column is displayed.
299 '[Program Block Range]' indicates the range of a program basic block.
304 --------
305 linkperf:perf-record[1], linkperf:perf-report[1]