[PATCH] riscv/mm: Simplify retry logic in do_page_fault()

[Pekka Enberg]

On Fri, Aug 21, 2020 at 6:32 AM Palmer Dabbelt <palmer at dabbelt.com> wrote:
>
> On Wed, 19 Aug 2020 07:10:11 PDT (-0700), penberg at gmail.com wrote:
> > From: Pekka Enberg <penberg at kernel.org>
> >
> > Let's combine the two retry logic if statements in do_page_fault() to
> > simplify the code.
> > ---
> >  arch/riscv/mm/fault.c | 20 +++++++++-----------
> >  1 file changed, 9 insertions(+), 11 deletions(-)
> >
> > diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
> > index 716d64e36f83..f5c2e4a249eb 100644
> > --- a/arch/riscv/mm/fault.c
> > +++ b/arch/riscv/mm/fault.c
> > @@ -127,17 +127,15 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
> >               BUG();
> >       }
> >
> > -     if (flags & FAULT_FLAG_ALLOW_RETRY) {
> > -             if (fault & VM_FAULT_RETRY) {
> > -                     flags |= FAULT_FLAG_TRIED;
> > -
> > -                     /*
> > -                      * No need to mmap_read_unlock(mm) as we would
> > -                      * have already released it in __lock_page_or_retry
> > -                      * in mm/filemap.c.
> > -                      */
> > -                     goto retry;
> > -             }
> > +     if (unlikely((fault & VM_FAULT_RETRY) && (flags & FAULT_FLAG_ALLOW_RETRY))) {
> > +             flags |= FAULT_FLAG_TRIED;
> > +
> > +             /*
> > +              * No need to mmap_read_unlock(mm) as we would
> > +              * have already released it in __lock_page_or_retry
> > +              * in mm/filemap.c.
> > +              */
> > +             goto retry;
> >       }
> >
> >       mmap_read_unlock(mm);
>
> This is missing your Signed-off-by, and while it's a bit pedantic I can't add
> it myself.  Otherwise
>
> Reviewed-by: Palmer Dabbelt <palmerdabbelt at google.com>
>
> Thanks!

Oh, sorry about that. Here you go:

Signed-off-by: Pekka Enberg <penberg at kernel.org>

I can also resend the patch with a SOB if you so prefer.

- Pekka