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| author | Alexander Duyck <alexander.h.duyck@redhat.com> | 2015-04-13 21:03:49 +0930 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2015-04-13 21:04:16 +0930 |
| commit | 9e1a27ea42691429e31f158cce6fc61bc79bb2e9 (patch) | |
| tree | 46b42dc8ad0ee34fafcf6d7228e51066a550f184 /include/linux/virtio_ring.h | |
| parent | a8557d32fe90a91d70dbbf57a034ad0c660ce237 (diff) | |
| download | linux-9e1a27ea42691429e31f158cce6fc61bc79bb2e9.tar.gz linux-9e1a27ea42691429e31f158cce6fc61bc79bb2e9.tar.bz2 linux-9e1a27ea42691429e31f158cce6fc61bc79bb2e9.zip | |
virtio_ring: Update weak barriers to use dma_wmb/rmb
This change makes it so that instead of using smp_wmb/rmb which varies
depending on the kernel configuration we can can use dma_wmb/rmb which for
most architectures should be equal to or slightly more strict than
smp_wmb/rmb.
The advantage to this is that these barriers are available to uniprocessor
builds as well so the performance should improve under such a
configuration.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'include/linux/virtio_ring.h')
| -rw-r--r-- | include/linux/virtio_ring.h | 23 |
1 files changed, 4 insertions, 19 deletions
diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h index 67e06fe18c03..8e50888a6d59 100644 --- a/include/linux/virtio_ring.h +++ b/include/linux/virtio_ring.h @@ -21,19 +21,20 @@ * actually quite cheap. */ -#ifdef CONFIG_SMP static inline void virtio_mb(bool weak_barriers) { +#ifdef CONFIG_SMP if (weak_barriers) smp_mb(); else +#endif mb(); } static inline void virtio_rmb(bool weak_barriers) { if (weak_barriers) - smp_rmb(); + dma_rmb(); else rmb(); } @@ -41,26 +42,10 @@ static inline void virtio_rmb(bool weak_barriers) static inline void virtio_wmb(bool weak_barriers) { if (weak_barriers) - smp_wmb(); + dma_wmb(); else wmb(); } -#else -static inline void virtio_mb(bool weak_barriers) -{ - mb(); -} - -static inline void virtio_rmb(bool weak_barriers) -{ - rmb(); -} - -static inline void virtio_wmb(bool weak_barriers) -{ - wmb(); -} -#endif struct virtio_device; struct virtqueue; |