Improve ZFS N-way mirror read performance + Load/Locality/Rotation

Freebsd Rev. 256956 by @stevenh - Improve ZFS N-way mirror read performance by using load and locality information. Reviewed by: gibbs, mav, will Sponsored by: Multiplay References: http://svnweb.freebsd.org/changeset/base/256956 openzfs#1487 openzfs#1803 http://open-zfs.org/wiki/Features#Improve_N-way_mirror_read_performance Ported by: Andrew Barnes <[email protected]> Closes openzfs#1803
b333z · Oct 30, 2013 · bbe360b · bbe360b
1 parent a35beed
commit bbe360b
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Showing 5 changed files with 249 additions and 111 deletions.
diff --git a/include/sys/vdev.h b/include/sys/vdev.h
@@ -117,6 +117,9 @@ extern void vdev_queue_init(vdev_t *vd);
 extern void vdev_queue_fini(vdev_t *vd);
 extern zio_t *vdev_queue_io(zio_t *zio);
 extern void vdev_queue_io_done(zio_t *zio);
+extern int vdev_queue_length(vdev_t *vd);
+extern uint64_t vdev_queue_lastoffset(vdev_t *vd);
+extern void vdev_queue_register_lastoffset(vdev_t *vd, zio_t *zio);
 
 extern void vdev_config_dirty(vdev_t *vd);
 extern void vdev_config_clean(vdev_t *vd);

diff --git a/include/sys/vdev_impl.h b/include/sys/vdev_impl.h
@@ -98,6 +98,7 @@ struct vdev_cache {
 	avl_tree_t	vc_offset_tree;
 	avl_tree_t	vc_lastused_tree;
 	kmutex_t	vc_lock;
+	uint64_t        vq_lastoffset;
 };
 
 struct vdev_queue {
@@ -109,6 +110,7 @@ struct vdev_queue {
 	hrtime_t	vq_io_delta_ts;
 	list_t		vq_io_list;
 	kmutex_t	vq_lock;
+	uint64_t	vq_lastoffset;
 };
 
 struct vdev_io {
@@ -207,6 +209,9 @@ struct vdev {
 	spa_aux_vdev_t	*vdev_aux;	/* for l2cache vdevs		*/
 	zio_t		*vdev_probe_zio; /* root of current probe	*/
 	vdev_aux_t	vdev_label_aux;	/* on-disk aux state		*/
+	uint16_t        vdev_rotation_rate; /* rotational rate of the media */
+#define        VDEV_RATE_UNKNOWN       0
+#define        VDEV_RATE_NON_ROTATING  1
 
 	/*
 	 * For DTrace to work in userland (libzpool) context, these fields must

diff --git a/module/zfs/vdev_disk.c b/module/zfs/vdev_disk.c
@@ -242,6 +242,7 @@ vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *max_psize,
 {
 	struct block_device *bdev = ERR_PTR(-ENXIO);
 	vdev_disk_t *vd;
+	struct request_queue *q;
 	int mode, block_size;
 
 	/* Must have a pathname and it must be absolute. */
@@ -311,6 +312,17 @@ vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *max_psize,
 	/* Try to set the io scheduler elevator algorithm */
 	(void) vdev_elevator_switch(v, zfs_vdev_scheduler);
 
+	v->vdev_rotation_rate = VDEV_RATE_UNKNOWN;
+
+	/* Determine if the device has low seek times */
+#ifdef HAVE_BLK_QUEUE_NONROT
+
+	q = bdev_get_queue(vd->vd_bdev);
+	if (blk_queue_nonrot(q))
+		v->vdev_rotation_rate = VDEV_RATE_NON_ROTATING;	
+
+#endif
+
 	return 0;
 }