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authorRusty Russell <rusty@rustcorp.com.au>2013-03-20 15:37:09 +1030
committerRusty Russell <rusty@rustcorp.com.au>2013-03-20 15:43:29 +1030
commit13816c768d46586e925b22736992258d6105ad2c (patch)
treefffb6c71e49b040f532885e6311c5d4886c5d219 /tools/virtio
parentc8164d8931fdee9ac5314708c4071adf1d997425 (diff)
downloadlinaro-lsk-13816c768d46586e925b22736992258d6105ad2c.tar.gz
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.h16
-rw-r--r--tools/virtio/linux/virtio.h7
2 files changed, 23 insertions, 0 deletions
diff --git a/tools/virtio/linux/scatterlist.h b/tools/virtio/linux/scatterlist.h
index b2cf7d0f613..68c9e2adc99 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 e4af6591f5f..5fa612ad932 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);