| Message ID | 20190416104748.26942-1-stefanha@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vhost/scsi: drop unnecessary smp_mb__after_atomic() | expand |
On 2019/4/16 下午6:47, Stefan Hajnoczi wrote: > The vhost_scsi.ko code used several atomic variables at one point. > Later they were dropped or converted to regular ints protected by a > mutex. > > The commit that made these changes left an unused smp_mb__after_atomic() > in vhost_scsi_set_endpoint(). It was previously used after incrementing > vhost_scsi->vhost_ref_cnt but this field has been dropped: > > - atomic_inc(&vs->vhost_ref_cnt); > smp_mb__after_atomic_inc(); > > Reported-by: Andrea Parri <andrea.parri@amarulasolutions.com> > Fixes: 101998f6fcd680 ("tcm_vhost: Post-merge review changes requested by MST") > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > --- > drivers/vhost/scsi.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c > index 618fb6461017..c090d177bd75 100644 > --- a/drivers/vhost/scsi.c > +++ b/drivers/vhost/scsi.c > @@ -1443,7 +1443,6 @@ vhost_scsi_set_endpoint(struct vhost_scsi *vs, > tpg->tv_tpg_vhost_count++; > tpg->vhost_scsi = vs; > vs_tpg[tpg->tport_tpgt] = tpg; > - smp_mb__after_atomic(); > match = true; > } > mutex_unlock(&tpg->tv_tpg_mutex); Looks like Paolo has sent an identical patch before this one. Thanks
On Wed, Apr 17, 2019 at 6:57 AM Jason Wang <jasowang@redhat.com> wrote: > On 2019/4/16 下午6:47, Stefan Hajnoczi wrote: > > The vhost_scsi.ko code used several atomic variables at one point. > > Later they were dropped or converted to regular ints protected by a > > mutex. > > > > The commit that made these changes left an unused smp_mb__after_atomic() > > in vhost_scsi_set_endpoint(). It was previously used after incrementing > > vhost_scsi->vhost_ref_cnt but this field has been dropped: > > > > - atomic_inc(&vs->vhost_ref_cnt); > > smp_mb__after_atomic_inc(); > > > > Reported-by: Andrea Parri <andrea.parri@amarulasolutions.com> > > Fixes: 101998f6fcd680 ("tcm_vhost: Post-merge review changes requested by MST") > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > > --- > > drivers/vhost/scsi.c | 1 - > > 1 file changed, 1 deletion(-) > > > > diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c > > index 618fb6461017..c090d177bd75 100644 > > --- a/drivers/vhost/scsi.c > > +++ b/drivers/vhost/scsi.c > > @@ -1443,7 +1443,6 @@ vhost_scsi_set_endpoint(struct vhost_scsi *vs, > > tpg->tv_tpg_vhost_count++; > > tpg->vhost_scsi = vs; > > vs_tpg[tpg->tport_tpgt] = tpg; > > - smp_mb__after_atomic(); > > match = true; > > } > > mutex_unlock(&tpg->tv_tpg_mutex); > > > Looks like Paolo has sent an identical patch before this one. Yes, Paolo's patch is fine. Stefan
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index 618fb6461017..c090d177bd75 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -1443,7 +1443,6 @@ vhost_scsi_set_endpoint(struct vhost_scsi *vs, tpg->tv_tpg_vhost_count++; tpg->vhost_scsi = vs; vs_tpg[tpg->tport_tpgt] = tpg; - smp_mb__after_atomic(); match = true; } mutex_unlock(&tpg->tv_tpg_mutex);
The vhost_scsi.ko code used several atomic variables at one point. Later they were dropped or converted to regular ints protected by a mutex. The commit that made these changes left an unused smp_mb__after_atomic() in vhost_scsi_set_endpoint(). It was previously used after incrementing vhost_scsi->vhost_ref_cnt but this field has been dropped: - atomic_inc(&vs->vhost_ref_cnt); smp_mb__after_atomic_inc(); Reported-by: Andrea Parri <andrea.parri@amarulasolutions.com> Fixes: 101998f6fcd680 ("tcm_vhost: Post-merge review changes requested by MST") Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> --- drivers/vhost/scsi.c | 1 - 1 file changed, 1 deletion(-)