Re: [Regression or Fix]perf: profiling stats sigificantly changed for aio_write/read(ext4) between 6.7.0-rc1 and 6.6.0

[David Wang]

At 2023-11-15 18:32:41, "Peter Zijlstra" <peterz@xxxxxxxxxxxxx> wrote:
>
>Namhyung, could you please take a look, you know how to operate this
>cgroup stuff.
>

More information,  I run the profiling with 8cpu machine on a SSD with ext4 filesystem :

# mkdir /sys/fs/cgroup/mytest
# echo $$ > /sys/fs/cgroup/mytest/cgroup.procs
## Start profiling targeting cgroup /sys/fs/cgroup/mytest   on another terminal
# fio --randrepeat=1 --ioengine=libaio --direct=1 --name=test  --bs=4k --iodepth=64 --size=1G --readwrite=randrw  --runtime=600 --numjobs=4 --time_based=1

I got a feeling that f06cc667f7990 would decrease total samples by 10%~20% when profiling IO benchmark within cgroup.


David Wang