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| author | Michael S. Tsirkin <mst@redhat.com> | 2010-02-01 07:21:02 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-02-14 22:42:53 -0800 |
| commit | 5659338c88963ea791118e5e11e314b24f90c3eb (patch) | |
| tree | 1fbaa549d012e2ba9cd327ed6ac5dbcc773a0244 /drivers/vhost/vhost.c | |
| parent | f10a1f2e7e93a35cb603b63090ff0e70a576a641 (diff) | |
| download | lwn-5659338c88963ea791118e5e11e314b24f90c3eb.tar.gz lwn-5659338c88963ea791118e5e11e314b24f90c3eb.zip | |
vhost-net: switch to smp barriers
vhost-net only uses memory barriers to control SMP effects
(communication with userspace potentially running on a different CPU),
so it should use SMP barriers and not mandatory barriers for memory
access ordering, as suggested by Documentation/memory-barriers.txt
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/vhost/vhost.c')
| -rw-r--r-- | drivers/vhost/vhost.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index c8c25dbc5857..6eb15259f5ae 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -685,7 +685,7 @@ int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, int i, r; /* Make sure data written is seen before log. */ - wmb(); + smp_wmb(); for (i = 0; i < log_num; ++i) { u64 l = min(log[i].len, len); r = log_write(vq->log_base, log[i].addr, l); @@ -884,7 +884,7 @@ unsigned vhost_get_vq_desc(struct vhost_dev *dev, struct vhost_virtqueue *vq, return vq->num; /* Only get avail ring entries after they have been exposed by guest. */ - rmb(); + smp_rmb(); /* Grab the next descriptor number they're advertising, and increment * the index we've seen. */ @@ -996,14 +996,14 @@ int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len) return -EFAULT; } /* Make sure buffer is written before we update index. */ - wmb(); + smp_wmb(); if (put_user(vq->last_used_idx + 1, &vq->used->idx)) { vq_err(vq, "Failed to increment used idx"); return -EFAULT; } if (unlikely(vq->log_used)) { /* Make sure data is seen before log. */ - wmb(); + smp_wmb(); log_write(vq->log_base, vq->log_addr + sizeof *vq->used->ring * (vq->last_used_idx % vq->num), sizeof *vq->used->ring); @@ -1060,7 +1060,7 @@ bool vhost_enable_notify(struct vhost_virtqueue *vq) } /* They could have slipped one in as we were doing that: make * sure it's written, then check again. */ - mb(); + smp_mb(); r = get_user(avail_idx, &vq->avail->idx); if (r) { vq_err(vq, "Failed to check avail idx at %p: %d\n", |