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284c4e18f5
Jiri points out that we don't need any time checking and time string
parsing if the --time option is not set. That makes sense.
This patch refactors the time range parsing code, move the duplicated
code from perf report and perf script to time_utils and check if --time
option is set before parsing the time string. This patch is no logic
change expected. So the usage of --time is same as before.
For example:
Select the first and second 10% time slices:
perf report --time 10%/1,10%/2
perf script --time 10%/1,10%/2
Select the slices from 0% to 10% and from 30% to 40%:
perf report --time 0%-10%,30%-40%
perf script --time 0%-10%,30%-40%
Select the time slices from timestamp 3971 to 3973
perf report --time 3971,3973
perf script --time 3971,3973
Committer testing:
Using the above examples, check before and after to see if it remains
the same:
$ perf record -F 10000 -- find . -name "*.[ch]" -exec cat {} + > /dev/null
[ perf record: Woken up 3 times to write data ]
[ perf record: Captured and wrote 1.626 MB perf.data (42392 samples) ]
$
$ perf report --time 10%/1,10%/2 > /tmp/report.before.1
$ perf script --time 10%/1,10%/2 > /tmp/script.before.1
$ perf report --time 0%-10%,30%-40% > /tmp/report.before.2
$ perf script --time 0%-10%,30%-40% > /tmp/script.before.2
$ perf report --time 180457.375844,180457.377717 > /tmp/report.before.3
$ perf script --time 180457.375844,180457.377717 > /tmp/script.before.3
For example, the 3rd test produces this slice:
$ cat /tmp/script.before.3
cat 3147 180457.375844: 2143 cycles:uppp: 7f79362590d9 cfree@GLIBC_2.2.5+0x9 (/usr/lib64/libc-2.28.so)
cat 3147 180457.375986: 2245 cycles:uppp: 558b70f3d86e [unknown] (/usr/bin/cat)
cat 3147 180457.376012: 2164 cycles:uppp: 7f7936257430 _int_malloc+0x8c0 (/usr/lib64/libc-2.28.so)
cat 3147 180457.376140: 2921 cycles:uppp: 558b70f3a554 [unknown] (/usr/bin/cat)
cat 3147 180457.376296: 2844 cycles:uppp: 7f7936258abe malloc+0x4e (/usr/lib64/libc-2.28.so)
cat 3147 180457.376431: 2717 cycles:uppp: 558b70f3b0ca [unknown] (/usr/bin/cat)
cat 3147 180457.376667: 2630 cycles:uppp: 558b70f3d86e [unknown] (/usr/bin/cat)
cat 3147 180457.376795: 2442 cycles:uppp: 7f79362bff55 read+0x15 (/usr/lib64/libc-2.28.so)
cat 3147 180457.376927: 2376 cycles:uppp: ffffffff9aa00163 [unknown] ([unknown])
cat 3147 180457.376954: 2307 cycles:uppp: 7f7936257438 _int_malloc+0x8c8 (/usr/lib64/libc-2.28.so)
cat 3147 180457.377116: 3091 cycles:uppp: 7f7936258a70 malloc+0x0 (/usr/lib64/libc-2.28.so)
cat 3147 180457.377362: 2945 cycles:uppp: 558b70f3a3b0 [unknown] (/usr/bin/cat)
cat 3147 180457.377517: 2727 cycles:uppp: 558b70f3a9aa [unknown] (/usr/bin/cat)
$
Install 'coreutils-debuginfo' to see cat's guts (symbols), but then, the
above chunk translates into this 'perf report' output:
$ cat /tmp/report.before.3
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 13 of event 'cycles:uppp' (time slices: 180457.375844,180457.377717)
# Event count (approx.): 33552
#
# Overhead Command Shared Object Symbol
# ........ ....... ................ ......................
#
17.69% cat libc-2.28.so [.] malloc
14.53% cat cat [.] 0x000000000000586e
13.33% cat libc-2.28.so [.] _int_malloc
8.78% cat cat [.] 0x00000000000023b0
8.71% cat cat [.] 0x0000000000002554
8.13% cat cat [.] 0x00000000000029aa
8.10% cat cat [.] 0x00000000000030ca
7.28% cat libc-2.28.so [.] read
7.08% cat [unknown] [k] 0xffffffff9aa00163
6.39% cat libc-2.28.so [.] cfree@GLIBC_2.2.5
#
# (Tip: Order by the overhead of source file name and line number: perf report -s srcline)
#
$
Now lets see after applying this patch, nothing should change:
$ perf report --time 10%/1,10%/2 > /tmp/report.after.1
$ perf script --time 10%/1,10%/2 > /tmp/script.after.1
$ perf report --time 0%-10%,30%-40% > /tmp/report.after.2
$ perf script --time 0%-10%,30%-40% > /tmp/script.after.2
$ perf report --time 180457.375844,180457.377717 > /tmp/report.after.3
$ perf script --time 180457.375844,180457.377717 > /tmp/script.after.3
$ diff -u /tmp/report.before.1 /tmp/report.after.1
$ diff -u /tmp/script.before.1 /tmp/script.after.1
$ diff -u /tmp/report.before.2 /tmp/report.after.2
--- /tmp/report.before.2 2019-03-01 11:01:53.526094883 -0300
+++ /tmp/report.after.2 2019-03-01 11:09:18.231770467 -0300
@@ -352,5 +352,5 @@
#
-# (Tip: Generate a script for your data: perf script -g <lang>)
+# (Tip: Treat branches as callchains: perf report --branch-history)
#
$ diff -u /tmp/script.before.2 /tmp/script.after.2
$ diff -u /tmp/report.before.3 /tmp/report.after.3
--- /tmp/report.before.3 2019-03-01 11:03:08.890045588 -0300
+++ /tmp/report.after.3 2019-03-01 11:09:40.660224002 -0300
@@ -22,5 +22,5 @@
#
-# (Tip: Order by the overhead of source file name and line number: perf report -s srcline)
+# (Tip: List events using substring match: perf list <keyword>)
#
$ diff -u /tmp/script.before.3 /tmp/script.after.3
$
Cool, just the 'perf report' tips changed, QED.
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1551435186-6008-1-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.