bd2cdf26b9
The curr_pid and cpu_last_switched are used only for the
'perf sched replay/latency/map'. Put their initialization in
perf_sched__{lat|map|replay () to reduce unnecessary actions in other
commands.
Simple functional testing:
# perf sched record perf bench sched messaging
# Running 'sched/messaging' benchmark:
# 20 sender and receiver processes per group
# 10 groups == 400 processes run
Total time: 0.209 [sec]
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 16.456 MB perf.data (147907 samples) ]
# perf sched lat
-------------------------------------------------------------------------------------------------------------------------------------------
Task | Runtime ms | Switches | Avg delay ms | Max delay ms | Max delay start | Max delay end |
-------------------------------------------------------------------------------------------------------------------------------------------
sched-messaging:(401) | 2990.699 ms | 38705 | avg: 0.661 ms | max: 67.046 ms | max start: 456532.624830 s | max end: 456532.691876 s
qemu-system-x86:(7) | 179.764 ms | 2191 | avg: 0.152 ms | max: 21.857 ms | max start: 456532.576434 s | max end: 456532.598291 s
sshd:48125 | 0.522 ms | 2 | avg: 0.037 ms | max: 0.046 ms | max start: 456532.514610 s | max end: 456532.514656 s
<SNIP>
ksoftirqd/11:82 | 0.063 ms | 1 | avg: 0.005 ms | max: 0.005 ms | max start: 456532.769366 s | max end: 456532.769371 s
kworker/9:0-mm_:34624 | 0.233 ms | 20 | avg: 0.004 ms | max: 0.007 ms | max start: 456532.690804 s | max end: 456532.690812 s
migration/13:93 | 0.000 ms | 1 | avg: 0.004 ms | max: 0.004 ms | max start: 456532.512669 s | max end: 456532.512674 s
-----------------------------------------------------------------------------------------------------------------
TOTAL: | 3180.750 ms | 41368 |
---------------------------------------------------
# echo $?
0
# perf sched map
*A0 456532.510141 secs A0 => migration/0:15
*. 456532.510171 secs . => swapper:0
. *B0 456532.510261 secs B0 => migration/1:21
. *. 456532.510279 secs
<SNIP>
L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 *L7 . . . . 456532.785979 secs
L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 *L7 . . . 456532.786054 secs
L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 *L7 . . 456532.786127 secs
L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 *L7 . 456532.786197 secs
L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 *L7 456532.786270 secs
# echo $?
0
# perf sched replay
run measurement overhead: 108 nsecs
sleep measurement overhead: 66473 nsecs
the run test took 1000002 nsecs
the sleep test took 1082686 nsecs
nr_run_events: 49334
nr_sleep_events: 50054
nr_wakeup_events: 34701
target-less wakeups: 165
multi-target wakeups: 766
task 0 ( swapper: 0), nr_events: 15419
task 1 ( swapper: 1), nr_events: 1
task 2 ( swapper: 2), nr_events: 1
<SNIP>
task 715 ( sched-messaging: 110248), nr_events: 1438
task 716 ( sched-messaging: 110249), nr_events: 512
task 717 ( sched-messaging: 110250), nr_events: 500
task 718 ( sched-messaging: 110251), nr_events: 537
task 719 ( sched-messaging: 110252), nr_events: 823
------------------------------------------------------------
#1 : 1325.288, ravg: 1325.29, cpu: 7823.35 / 7823.35
#2 : 1363.606, ravg: 1329.12, cpu: 7655.53 / 7806.56
#3 : 1349.494, ravg: 1331.16, cpu: 7544.80 / 7780.39
#4 : 1311.488, ravg: 1329.19, cpu: 7495.13 / 7751.86
#5 : 1309.902, ravg: 1327.26, cpu: 7266.65 / 7703.34
#6 : 1309.535, ravg: 1325.49, cpu: 7843.86 / 7717.39
#7 : 1316.482, ravg: 1324.59, cpu: 7854.41 / 7731.09
#8 : 1366.604, ravg: 1328.79, cpu: 7955.81 / 7753.57
#9 : 1326.286, ravg: 1328.54, cpu: 7466.86 / 7724.90
#10 : 1356.653, ravg: 1331.35, cpu: 7566.60 / 7709.07
# echo $?
0
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240206083228.172607-5-yangjihong1@huawei.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.