Re: [BUG bisected] sysfs: cannot create duplicate filename '/devices/virtual/workqueue/scsi_tmf_1073822488'

[Tejun Heo]

On Tue, Aug 20, 2024 at 07:16:00PM -0700, Paul E. McKenney wrote:
> Running rcutorture scenario TREE01 on next-20240820 on a dual-socket x86
> system (and for that matter on my laptop) got me this warning during boot:
> 
> sysfs: cannot create duplicate filename '/devices/virtual/workqueue/scsi_tmf_1073822488'
> 
> The number at the end varies from run to run.
> 
> Bisection landed here:
> 
> b188c57af2b5 ("workqueue: Split alloc_workqueue into internal function and lockdep init")
> 
> My reproducer is to run this at the top of the Linux-kernel file tree:
> 
> tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration 1m --configs "2*TREE01" --trust-make
> 
> Reverting this commit on top of next-20240820 gets me clean runs.
> 
> I cannot see how the patch would make this happen, but then again,
> I don't know this code at all well.
> 
> Thoughts?

Hmmm... I have a hard time imagining that change causing that error. My bet
is unreliable reproducer. I'll try the repro.

Thanks.

-- 
tejun