Re: [PATCH] locking/arch: Move qrwlock.h include after qspinlock.h

Ben Gardon
2021-02-10T17:37:11Z

On Wed, Feb 10, 2021 at 7:54 AM Waiman Long <longman@redhat.com> wrote:
>
> On 2/10/21 10:05 AM, Guenter Roeck wrote:
> > On 2/10/21 6:45 AM, Waiman Long wrote:
> >> The queued rwlock code has a dependency on the current spinlock
> >> implementation (likely to be qspinlock), but not vice versa. Including
> >> qrwlock.h before qspinlock.h can be problematic when expanding qrwlock
> >> functionality.
> >>
> >> If both qspinlock.h and qrwlock.h are to be included, the qrwlock.h
> >> include should always be after qspinlock.h. Update the current set of
> >> asm/spinlock.h files to enforce that.
> >>
> >> Signed-off-by: Waiman Long <longman@redhat.com>
> > There should be a Fixes: tag here. If the SHA of the offending commit is not
> > stable, there should be a better reference than "The queued rwlock code".
> I originally have a Fixes tag when I was modifying the mips'
> asm/spinlock.h file. After I realize that there are more files to
> modify, I take that out. Anyway, the problem was exposed by Ben's
> qrwlock patch. So existing stable releases should still be fine without
> this patch.
> >
> > This patch fixes the build problem I had observed on mips. I also tested
> > xtensa:defconfig and arm64:defconfig with no problems observed.
> >
> > Tested-by: Guenter Roeck <linux@roeck-us.net>
>
> Thanks for the testing as I don't have a build environment to verify that.
>
> Cheers,
> Longman
>

Thanks Longman and Guenter for developing and testing this fix! I
don't have the environment to test this either, but the patch looks
good to me.
Reviewed-by: Ben Gardon <bgardon@google.com>