| Message ID | 1556568902-12464-3-git-send-email-andrea.parri@amarulasolutions.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | None | expand |
On Mon, Apr 29, 2019 at 10:14:58PM +0200, Andrea Parri wrote: > This barrier only applies to the read-modify-write operations; in > particular, it does not apply to the atomic_set() primitive. > > Replace the barrier with an smp_mb(). > @@ -224,7 +224,7 @@ static inline void bio_cnt_set(struct bio *bio, unsigned int count) > { > if (count != 1) { > bio->bi_flags |= (1 << BIO_REFFED); > - smp_mb__before_atomic(); Maybe also add: /* * XXX the comment that explain this barrier goes here */ > + smp_mb(); > } > atomic_set(&bio->__bi_cnt, count); > }
On Mon, Apr 29, 2019 at 10:14:58PM +0200, Andrea Parri wrote: > This barrier only applies to the read-modify-write operations; in > particular, it does not apply to the atomic_set() primitive. > > Replace the barrier with an smp_mb(). > > Fixes: dac56212e8127 ("bio: skip atomic inc/dec of ->bi_cnt for most use cases") > Cc: stable@vger.kernel.org > Reported-by: "Paul E. McKenney" <paulmck@linux.ibm.com> > Reported-by: Peter Zijlstra <peterz@infradead.org> > Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com> > Cc: Jens Axboe <axboe@kernel.dk> > Cc: linux-block@vger.kernel.org Jens: any suggestions to move this patch forward? Thanx, Andrea > --- > include/linux/bio.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/bio.h b/include/linux/bio.h > index e584673c18814..5becbafb84e8a 100644 > --- a/include/linux/bio.h > +++ b/include/linux/bio.h > @@ -224,7 +224,7 @@ static inline void bio_cnt_set(struct bio *bio, unsigned int count) > { > if (count != 1) { > bio->bi_flags |= (1 << BIO_REFFED); > - smp_mb__before_atomic(); > + smp_mb(); > } > atomic_set(&bio->__bi_cnt, count); > } > -- > 2.7.4 >
On Mon, Apr 29, 2019 at 10:14:58PM +0200, Andrea Parri wrote: > This barrier only applies to the read-modify-write operations; in > particular, it does not apply to the atomic_set() primitive. > > Replace the barrier with an smp_mb(). > > Fixes: dac56212e8127 ("bio: skip atomic inc/dec of ->bi_cnt for most use cases") > Cc: stable@vger.kernel.org > Reported-by: "Paul E. McKenney" <paulmck@linux.ibm.com> > Reported-by: Peter Zijlstra <peterz@infradead.org> > Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com> > Cc: Jens Axboe <axboe@kernel.dk> > Cc: linux-block@vger.kernel.org > --- > include/linux/bio.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/bio.h b/include/linux/bio.h > index e584673c18814..5becbafb84e8a 100644 > --- a/include/linux/bio.h > +++ b/include/linux/bio.h > @@ -224,7 +224,7 @@ static inline void bio_cnt_set(struct bio *bio, unsigned int count) > { > if (count != 1) { > bio->bi_flags |= (1 << BIO_REFFED); > - smp_mb__before_atomic(); > + smp_mb(); > } > atomic_set(&bio->__bi_cnt, count); > } > -- > 2.7.4 > Looks fine, Reviewed-by: Ming Lei <ming.lei@redhat.com> Thanks, Ming
diff --git a/include/linux/bio.h b/include/linux/bio.h index e584673c18814..5becbafb84e8a 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -224,7 +224,7 @@ static inline void bio_cnt_set(struct bio *bio, unsigned int count) { if (count != 1) { bio->bi_flags |= (1 << BIO_REFFED); - smp_mb__before_atomic(); + smp_mb(); } atomic_set(&bio->__bi_cnt, count); }
This barrier only applies to the read-modify-write operations; in particular, it does not apply to the atomic_set() primitive. Replace the barrier with an smp_mb(). Fixes: dac56212e8127 ("bio: skip atomic inc/dec of ->bi_cnt for most use cases") Cc: stable@vger.kernel.org Reported-by: "Paul E. McKenney" <paulmck@linux.ibm.com> Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org --- include/linux/bio.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)