Re: [PATCH 1/1] [RFC] workqueue: fix ghost PENDING flag while doing MQ IO

From: Roman Penyaev
Date: Mon Apr 25 2016 - 12:41:24 EST


On Mon, Apr 25, 2016 at 6:00 PM, Tejun Heo <tj@xxxxxxxxxx> wrote:
> On Mon, Apr 25, 2016 at 11:48:47AM -0400, Tejun Heo wrote:
>> Heh, excellent debugging. I wonder how old this bug is. cc'ing David
>
> I just went through the history. So, we used to have clear_bit()
> instead of atomic_long_set() but clear_bit() doesn't imply any barrier
> either, so kudos to you. You just debugged an issue which is most
> likely has been there for over a decade! :)

That's nice, that we can finally fix it.
But as I was saying I was just lucky enough to have very easy reproduction.
I could check all crazy ideas I had :)

--
Roman