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| author | Rusty Russell <rusty@rustcorp.com.au> | 2013-03-20 06:07:09 +0100 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2013-03-20 06:13:29 +0100 |
| commit | 13816c768d46586e925b22736992258d6105ad2c (patch) | |
| tree | fffb6c71e49b040f532885e6311c5d4886c5d219 /tools/virtio | |
| parent | scatterlist: introduce sg_unmark_end (diff) | |
| download | linux-13816c768d46586e925b22736992258d6105ad2c.tar.xz linux-13816c768d46586e925b22736992258d6105ad2c.zip | |
virtio_ring: virtqueue_add_sgs, to add multiple sgs.
virtio_scsi can really use this, to avoid the current hack of copying
the whole sg array. Some other things get slightly neater, too.
This causes a slowdown in virtqueue_add_buf(), which is implemented as
a wrapper. This is addressed in the next patches.
for i in `seq 50`; do /usr/bin/time -f 'Wall time:%e' ./vringh_test --indirect --eventidx --parallel --fast-vringh; done 2>&1 | stats --trim-outliers:
Before:
Using CPUS 0 and 3
Guest: notified 0, pinged 39009-39063(39062)
Host: notified 39009-39063(39062), pinged 0
Wall time:1.700000-1.950000(1.723542)
After:
Using CPUS 0 and 3
Guest: notified 0, pinged 39062-39063(39063)
Host: notified 39062-39063(39063), pinged 0
Wall time:1.760000-2.220000(1.789167)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Reviewed-by: Asias He <asias@redhat.com>
Diffstat (limited to 'tools/virtio')
| -rw-r--r-- | tools/virtio/linux/scatterlist.h | 16 | ||||
| -rw-r--r-- | tools/virtio/linux/virtio.h | 7 |
2 files changed, 23 insertions, 0 deletions
diff --git a/tools/virtio/linux/scatterlist.h b/tools/virtio/linux/scatterlist.h index b2cf7d0f6133..68c9e2adc996 100644 --- a/tools/virtio/linux/scatterlist.h +++ b/tools/virtio/linux/scatterlist.h @@ -125,6 +125,22 @@ static inline void sg_mark_end(struct scatterlist *sg) sg->page_link &= ~0x01; } +/** + * sg_unmark_end - Undo setting the end of the scatterlist + * @sg: SG entryScatterlist + * + * Description: + * Removes the termination marker from the given entry of the scatterlist. + * + **/ +static inline void sg_unmark_end(struct scatterlist *sg) +{ +#ifdef CONFIG_DEBUG_SG + BUG_ON(sg->sg_magic != SG_MAGIC); +#endif + sg->page_link &= ~0x02; +} + static inline struct scatterlist *sg_next(struct scatterlist *sg) { #ifdef CONFIG_DEBUG_SG diff --git a/tools/virtio/linux/virtio.h b/tools/virtio/linux/virtio.h index e4af6591f5ff..5fa612ad932c 100644 --- a/tools/virtio/linux/virtio.h +++ b/tools/virtio/linux/virtio.h @@ -56,6 +56,13 @@ int virtqueue_add_buf(struct virtqueue *vq, void *data, gfp_t gfp); +int virtqueue_add_sgs(struct virtqueue *vq, + struct scatterlist *sgs[], + unsigned int out_sgs, + unsigned int in_sgs, + void *data, + gfp_t gfp); + void virtqueue_kick(struct virtqueue *vq); void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len); |