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

[Zheng Yejian <zhengyejian1@huawei.com>]

On 2023/9/6 21:02, Steven Rostedt wrote:
> On Wed, 6 Sep 2023 08:56:21 -0400
> Steven Rostedt <rostedt@goodmis.org> wrote:
> 
>> On Wed, 6 Sep 2023 19:57:24 +0800
>> Zheng Yejian <zhengyejian1@huawei.com> 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
>