Re: [PATCH v9 4/4] xfs: replace mrlock_t with rw_semaphores

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Thu, Oct 08, 2020 at 03:55:16PM +0200, Pavel Reichl wrote:
> 
> >> Hi,
> >>
> >> thanks for the comments, however for some reason I cannot reproduce
> >> the same memory corruption you are getting.
> > 
> > <shrug> Do you have full preempt enabled?
> 
> Hi, I'm not proud to admit that until now I tested w/o 'CONFIG_PREEMPT=y' :-/
> However at least now I can see the bug you hit and test that the
> proposed change in version #10 fixes that.

<shrug> That just means you get to hit all the stall warnings (which are
fixable with cond_resched()) that I rarely see because preempt kernels
can reschedule at will... :)

> 
> 
> > 
> >> Do you think that moving the 'rwsem_release()' right before the
> >> 'complete()' should fix the problem?
> >>
> >> Something like:
> >>
> >>
> >> +       /*
> >> +        * Update lockdep's lock ownership information to point to
> >> +        * this thread as the thread that scheduled this worker is waiting
> >> +        * for it's completion.
> > 
> > Nit: "it's" is always a contraction of "it is"; "its" is correct
> > (posessive) form here.
> 
> Thanks for noticing. I know the difference...but still I did this
> mistake. I must focus more next time.

No worries, English is a weird language.

"Inflammable means flammable?  What a country!"
          -- Dr. Nick Riviera

--D

> 
> > 
> > Otherwise, this looks fine to me.
> 
> Thanks, version #10 is on list now.
> 
> Bye.
>