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authorJin Yao <yao.jin@linux.intel.com>2019-03-05 21:05:41 +0800
committerArnaldo Carvalho de Melo <acme@redhat.com>2019-03-06 18:03:23 -0300
commit4802138d78caed36cee2a859f77fb2035f230018 (patch)
tree5de7673784647494ff6605fcec6472c26d62f8cf /tools/perf/Documentation
parent153259382633ecbbc0af4f3f0b6515757ebe2984 (diff)
downloadlinux-4802138d78caed36cee2a859f77fb2035f230018.tar.bz2
perf diff: Support --time filter option
To improve 'perf diff', implement a --time filter option to diff the samples within given time window. It supports time percent with multiple time ranges. The time string format is 'a%/n,b%/m,...' or 'a%-b%,c%-%d,...'. For example: Select the second 10% time slice to diff: perf diff --time 10%/2 Select from 0% to 10% time slice to diff: perf diff --time 0%-10% Select the first and the second 10% time slices to diff: perf diff --time 10%/1,10%/2 Select from 0% to 10% and 30% to 40% slices to diff: perf diff --time 0%-10%,30%-40% It also supports analysing samples within a given time window <start>,<stop>. Times have the format seconds.microseconds. If 'start' is not given (i.e., time string is ',x.y') then analysis starts at the beginning of the file. If the stop time is not given (i.e, time string is 'x.y,') then analysis goes to end of file. Time string is 'a1.b1,c1.d1:a2.b2,c2.d2'. Use ':' to separate timestamps for different perf.data files. For example, we get the timestamp information from perf script. perf script -i perf.data.old mgen 13940 [000] 3946.361400: ... perf script -i perf.data mgen 13940 [000] 3971.150589 ... perf diff --time 3946.361400,:3971.150589, It analyzes the perf.data.old from the timestamp 3946.361400 to the end of perf.data.old and analyzes the perf.data from the timestamp 3971.150589 to the end of perf.data. v4: --- Update abstime_str_dup(), let it return error if strdup is failed, and update __cmd_diff() accordingly. Signed-off-by: Jin Yao <yao.jin@linux.intel.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jin Yao <yao.jin@intel.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1551791143-10334-2-git-send-email-yao.jin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation')
-rw-r--r--tools/perf/Documentation/perf-diff.txt45
1 files changed, 45 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-diff.txt b/tools/perf/Documentation/perf-diff.txt
index a79c84ae61aa..036d65bded51 100644
--- a/tools/perf/Documentation/perf-diff.txt
+++ b/tools/perf/Documentation/perf-diff.txt
@@ -118,6 +118,51 @@ OPTIONS
sum of shown entries will be always 100%. "absolute" means it retains
the original value before and after the filter is applied.
+--time::
+ Analyze samples within given time window. It supports time
+ percent with multiple time ranges. Time string is 'a%/n,b%/m,...'
+ or 'a%-b%,c%-%d,...'.
+
+ For example:
+
+ Select the second 10% time slice to diff:
+
+ perf diff --time 10%/2
+
+ Select from 0% to 10% time slice to diff:
+
+ perf diff --time 0%-10%
+
+ Select the first and the second 10% time slices to diff:
+
+ perf diff --time 10%/1,10%/2
+
+ Select from 0% to 10% and 30% to 40% slices to diff:
+
+ perf diff --time 0%-10%,30%-40%
+
+ It also supports analyzing samples within a given time window
+ <start>,<stop>. Times have the format seconds.microseconds. If 'start'
+ is not given (i.e., time string is ',x.y') then analysis starts at
+ the beginning of the file. If stop time is not given (i.e, time
+ string is 'x.y,') then analysis goes to the end of the file. Time string is
+ 'a1.b1,c1.d1:a2.b2,c2.d2'. Use ':' to separate timestamps for different
+ perf.data files.
+
+ For example, we get the timestamp information from 'perf script'.
+
+ perf script -i perf.data.old
+ mgen 13940 [000] 3946.361400: ...
+
+ perf script -i perf.data
+ mgen 13940 [000] 3971.150589 ...
+
+ perf diff --time 3946.361400,:3971.150589,
+
+ It analyzes the perf.data.old from the timestamp 3946.361400 to
+ the end of perf.data.old and analyzes the perf.data from the
+ timestamp 3971.150589 to the end of perf.data.
+
COMPARISON
----------
The comparison is governed by the baseline file. The baseline perf.data