Re: waitqueue lockdep annotation

[Jason Baron]

On 12/01/2017 06:03 PM, Christoph Hellwig wrote:
> On Fri, Dec 01, 2017 at 05:34:50PM -0500, Jason Baron wrote:
>> hmmm...I'm not sure how this suggestion would change the locking rules
>> from what we currently have. Right now, we use ep->lock, if we remove
>> that and use ep->wq->lock instead, there is just a 1-to-1 mapping there
>> that has not changed, since ep->wq->lock currently is completely not
>> being used.
> 
> True.  The patch below survives the amazing complex booting and starting
> systemd with lockdep enabled test.  Do we have something resembling a
> epoll test suite?
>

I don't think we have any in the kernel tree proper (other than some
selftests using epoll) but there are tests in ltp and some performance
tests such as:

http://linux-scalability.org/epoll/epoll-test.c
http://www.xmailserver.org/linux-patches/pipetest.c

Thanks,

-Jason