From 244b2c5ca8b14627e4a17755e5922221e121c771 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 09 Oct 2024 06:15:07 +0000
Subject: [PATCH] change system file
---
kernel/tools/perf/Documentation/perf-diff.txt | 84 ++++++++++++++++++++++++++++++++++++++++-
1 files changed, 81 insertions(+), 3 deletions(-)
diff --git a/kernel/tools/perf/Documentation/perf-diff.txt b/kernel/tools/perf/Documentation/perf-diff.txt
index a79c84a..be65bd5 100644
--- a/kernel/tools/perf/Documentation/perf-diff.txt
+++ b/kernel/tools/perf/Documentation/perf-diff.txt
@@ -90,9 +90,15 @@
-c::
--compute::
- Differential computation selection - delta, ratio, wdiff, delta-abs
- (default is delta-abs). Default can be changed using diff.compute
- config option. See COMPARISON METHODS section for more info.
+ Differential computation selection - delta, ratio, wdiff, cycles,
+ delta-abs (default is delta-abs). Default can be changed using
+ diff.compute config option. See COMPARISON METHODS section for
+ more info.
+
+--cycles-hist::
+ Report a histogram and the standard deviation for cycles data.
+ It can help us to judge if the reported cycles data is noisy or
+ not. This option should be used with '-c cycles'.
-p::
--period::
@@ -117,6 +123,68 @@
"relative" means it's relative to filtered entries only so that the
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.nanoseconds. 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.
+ Multiple ranges can be separated by spaces, which requires the argument
+ to be quoted e.g. --time "1234.567,1234.789 1235,"
+ 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.
+
+--cpu:: Only diff samples for the list of CPUs provided. Multiple CPUs can
+ be provided as a comma-separated list with no space: 0,1. Ranges of
+ CPUs are specified with -: 0-2. Default is to report samples on all
+ CPUs.
+
+--pid=::
+ Only diff samples for given process ID (comma separated list).
+
+--tid=::
+ Only diff samples for given thread ID (comma separated list).
+
+--stream::
+ Enable hot streams comparison. Stream can be a callchain which is
+ aggregated by the branch records from samples.
COMPARISON
----------
@@ -222,6 +290,16 @@
- WEIGHT-A being the weight of the data file
- WEIGHT-B being the weight of the baseline data file
+cycles
+~~~~~~
+If specified the '[Program Block Range] Cycles Diff' column is displayed.
+It displays the cycles difference of same program basic block amongst
+two perf.data. The program basic block is the code between two branches.
+
+'[Program Block Range]' indicates the range of a program basic block.
+Source line is reported if it can be found otherwise uses symbol+offset
+instead.
+
SEE ALSO
--------
linkperf:perf-record[1], linkperf:perf-report[1]
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