Re: [PATCH] selftests/ftrace: Correctly enable event in instance-event.tc

[Zheng Yejian]

On 2023/9/6 21:02, Steven Rostedt wrote:
> On Wed, 6 Sep 2023 08:56:21 -0400
> Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> > On Wed, 6 Sep 2023 19:57:24 +0800
> > Zheng Yejian <zhengyejian1@xxxxxxxxxx> wrote:
> >
> > > BTW, I do reproduce with following testcase fix, then just run:
> > > ./ftracetest test.d/instances/instance-event.tc
> > > diff --git
> > > a/tools/testing/selftests/ftrace/test.d/instances/instance-event.tc
> > > b/tools/testing/selftests/ftrace/test.d/instances/instance-event.tc
> > > index 0eb47fbb3f44..42422e425107 100644
> > > --- a/tools/testing/selftests/ftrace/test.d/instances/instance-event.tc
> > > +++ b/tools/testing/selftests/ftrace/test.d/instances/instance-event.tc
> > > @@ -39,7 +39,7 @@ instance_read() {
> > >
> > >    instance_set() {
> > >            while :; do
> > > -                echo 1 > foo/events/sched/sched_switch
> > > +                echo 1 > foo/events/sched/sched_switch/enable
> > >            done 2> /dev/null
> > >    }
> >
> > Ah thanks. I didn't have that on my test box :-p
> >
> > Although I'm still having issues reproducing it. Do you have anything
> > special on your kernel command line?

I can reproduce it on qemu, boot command seems nothing special (replace
${kernel} with bzImage path and replace ${rootfs} with a ubuntu image):

qemu-system-x86_64 -M pc -m 8G -enable-kvm -smp cpus=12 -kernel 
${kernel} -drive file=${rootfs},if=virtio,format=raw,id=hd0 -fsdev 
local,security_model=passthrough,id=fsdev0,path=/home/test -nographic 
-append "rootwait root=/dev/vda rw console=ttyS0 rodata=off"

> Also, which branch are you testing? What's the sha of the code you are testing?

I think it can be reproduced after any commit after commit
27152bceea1d ("eventfs: Move tracing/events to eventfs")

also can be reproduced with the newest:
65d6e954e378 ("Merge tag 'gfs2-v6.5-rc5-fixes' of 
git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2")

And revert commit 27152bceea1d ("eventfs: Move tracing/events to
eventfs"), the issue just seems gone.

--

Thanks,
Zheng Yejian

> -- Steve