Re: [PATCH] perf bench sched pipe: Add -G/--cgroups option

[Namhyung Kim]

On Fri, Oct 13, 2023 at 4:03 PM Arnaldo Carvalho de Melo
<acme@xxxxxxxxxx> wrote:
>
> Em Fri, Oct 13, 2023 at 03:57:27PM -0700, Namhyung Kim escreveu:
> > Hi Arnaldo,
> >
> > On Fri, Oct 13, 2023 at 3:41 PM Arnaldo Carvalho de Melo
> > <acme@xxxxxxxxxx> wrote:
> > > -rw-r--r--. 1 root root 0 Oct 13 19:22 /sys/fs/cgroup/AAA/cgroup.procs
> > > [root@quaco ~]# ls -la /sys/fs/cgroup/AAA/cgroup.threads
> > > -rw-r--r--. 1 root root 0 Oct 13 19:22 /sys/fs/cgroup/AAA/cgroup.threads
> > > [root@quaco ~]# ls -la /sys/fs/cgroup/BBB/cgroup.threads
> > > -rw-r--r--. 1 root root 0 Oct 13 19:22 /sys/fs/cgroup/BBB/cgroup.threads
> > > [root@quaco ~]# ls -la /sys/fs/cgroup/BBB/cgroup.procs
> > > -rw-r--r--. 1 root root 0 Oct 13 19:22 /sys/fs/cgroup/BBB/cgroup.procs
> > > [root@quaco ~]#
> > >
> > > [root@quaco ~]# perf bench sched pipe -G AAA,BBB
> > > # Running 'sched/pipe' benchmark:
> > > cannot enter to cgroup: AAA (written=-1, len=6, errno=Operation not supported)
> > > cannot enter to cgroup: BBB (written=-1, len=6, errno=Operation not supported)
> > > # Executed 1000000 pipe operations between two processes
> > >
> > >      Total time: 6.303 [sec]
> > >
> > >        6.303221 usecs/op
> > >          158649 ops/sec
> > > [root@quaco ~]#
> > >
> > > I'm certainly missing something here :-\
> >
> > Try to enable some cgroup controllers first.  Like
> >
> >   # echo +cpu > /sys/fs/cgroup/AAA/cgroup.subtree_control
> >   # echo +cpu > /sys/fs/cgroup/BBB/cgroup.subtree_control
>
> [root@quaco cgroup]# echo +cpu > /sys/fs/cgroup/AAA/cgroup.subtree_control
> [root@quaco cgroup]# echo +cpu > /sys/fs/cgroup/BBB/cgroup.subtree_control
> [root@quaco cgroup]# perf bench sched pipe -G AAA,BBB
> # Running 'sched/pipe' benchmark:
> cannot enter to cgroup: AAA (written=-1, len=6, errno=Operation not supported)
> cannot enter to cgroup: BBB (written=-1, len=6, errno=Operation not supported)
> # Executed 1000000 pipe operations between two processes
>
>      Total time: 6.267 [sec]
>
>        6.267680 usecs/op
>          159548 ops/sec
> [root@quaco cgroup]# cat /sys/fs/cgroup/AAA/cgroup.subtree_control
> cpu
> [root@quaco cgroup]# cat /sys/fs/cgroup/BBB/cgroup.subtree_control
> cpu
> [root@quaco cgroup]# uname -a
> Linux quaco 6.5.6-200.fc38.x86_64 #1 SMP PREEMPT_DYNAMIC Fri Oct  6 19:02:35 UTC 2023 x86_64 GNU/Linux
> [root@quaco cgroup]#

Hmm... I don't know, I've tested it on v1 only ;-p  I'll take a look.

Also I found a bug, will fix too.

Thanks,
Namhyung


diff --git a/tools/perf/bench/sched-pipe.c b/tools/perf/bench/sched-pipe.c
index 1103fd658d5d..25236f339b90 100644
--- a/tools/perf/bench/sched-pipe.c
+++ b/tools/perf/bench/sched-pipe.c
@@ -118,9 +118,9 @@ static void enter_cgroup(struct cgroup *cgrp)

        /* try cgroup v2 interface first */
        if (threaded)
-               fd = openat(cgrp->fd, "cgroup.procs", O_WRONLY);
-       else
                fd = openat(cgrp->fd, "cgroup.threads", O_WRONLY);
+       else
+               fd = openat(cgrp->fd, "cgroup.progs", O_WRONLY);

        /* try cgroup v1 if failed */
        if (fd < 0)