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authorGvozden Neskovic <[email protected]>2017-08-04 11:29:56 +0200
committerBrian Behlendorf <[email protected]>2017-08-21 10:05:16 -0700
commitd6c6590c5dd727832a58e77f7830049631b0c266 (patch)
tree8c93caff9a7b52c60764fc355f2931b1265e4697 /module
parent133a5c6598ddc858f5b7ecedaf1364fcfe2e477f (diff)
vdev_mirror: load balancing fixes
vdev_queue: - Track the last position of each vdev, including the io size, in order to detect linear access of the following zio. - Remove duplicate `vq_lastoffset` vdev_mirror: - Correctly calculate the zio offset (signedness issue) - Deprecate `vdev_queue_register_lastoffset()` - Add `VDEV_LABEL_START_SIZE` to zio offset of leaf vdevs Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Gvozden Neskovic <[email protected]> Closes #6461
Diffstat (limited to 'module')
-rw-r--r--module/zfs/vdev_mirror.c36
-rw-r--r--module/zfs/vdev_queue.c21
2 files changed, 23 insertions, 34 deletions
diff --git a/module/zfs/vdev_mirror.c b/module/zfs/vdev_mirror.c
index 15d1f204f..0cf2bc665 100644
--- a/module/zfs/vdev_mirror.c
+++ b/module/zfs/vdev_mirror.c
@@ -116,7 +116,8 @@ static const zio_vsd_ops_t vdev_mirror_vsd_ops = {
static int
vdev_mirror_load(mirror_map_t *mm, vdev_t *vd, uint64_t zio_offset)
{
- uint64_t lastoffset;
+ uint64_t last_offset;
+ int64_t offset_diff;
int load;
/* All DVAs have equal weight at the root. */
@@ -129,13 +130,17 @@ vdev_mirror_load(mirror_map_t *mm, vdev_t *vd, uint64_t zio_offset)
* worse overall when resilvering with compared to without.
*/
+ /* Fix zio_offset for leaf vdevs */
+ if (vd->vdev_ops->vdev_op_leaf)
+ zio_offset += VDEV_LABEL_START_SIZE;
+
/* Standard load based on pending queue length. */
load = vdev_queue_length(vd);
- lastoffset = vdev_queue_lastoffset(vd);
+ last_offset = vdev_queue_last_offset(vd);
if (vd->vdev_nonrot) {
/* Non-rotating media. */
- if (lastoffset == zio_offset)
+ if (last_offset == zio_offset)
return (load + zfs_vdev_mirror_non_rotating_inc);
/*
@@ -148,16 +153,16 @@ vdev_mirror_load(mirror_map_t *mm, vdev_t *vd, uint64_t zio_offset)
}
/* Rotating media I/O's which directly follow the last I/O. */
- if (lastoffset == zio_offset)
+ if (last_offset == zio_offset)
return (load + zfs_vdev_mirror_rotating_inc);
/*
* Apply half the seek increment to I/O's within seek offset
- * of the last I/O queued to this vdev as they should incur less
+ * of the last I/O issued to this vdev as they should incur less
* of a seek increment.
*/
- if (ABS(lastoffset - zio_offset) <
- zfs_vdev_mirror_rotating_seek_offset)
+ offset_diff = (int64_t)(last_offset - zio_offset);
+ if (ABS(offset_diff) < zfs_vdev_mirror_rotating_seek_offset)
return (load + (zfs_vdev_mirror_rotating_seek_inc / 2));
/* Apply the full seek increment to all other I/O's. */
@@ -382,29 +387,20 @@ vdev_mirror_child_select(zio_t *zio)
mm->mm_preferred_cnt++;
}
- if (mm->mm_preferred_cnt == 1) {
- vdev_queue_register_lastoffset(
- mm->mm_child[mm->mm_preferred[0]].mc_vd, zio);
+ if (mm->mm_preferred_cnt == 1)
return (mm->mm_preferred[0]);
- }
- if (mm->mm_preferred_cnt > 1) {
- int c = vdev_mirror_preferred_child_randomize(zio);
- vdev_queue_register_lastoffset(mm->mm_child[c].mc_vd, zio);
- return (c);
- }
+ if (mm->mm_preferred_cnt > 1)
+ return (vdev_mirror_preferred_child_randomize(zio));
/*
* Every device is either missing or has this txg in its DTL.
* Look for any child we haven't already tried before giving up.
*/
for (c = 0; c < mm->mm_children; c++) {
- if (!mm->mm_child[c].mc_tried) {
- vdev_queue_register_lastoffset(mm->mm_child[c].mc_vd,
- zio);
+ if (!mm->mm_child[c].mc_tried)
return (c);
- }
}
/*
diff --git a/module/zfs/vdev_queue.c b/module/zfs/vdev_queue.c
index 6b3e87291..40cba340a 100644
--- a/module/zfs/vdev_queue.c
+++ b/module/zfs/vdev_queue.c
@@ -393,7 +393,7 @@ vdev_queue_init(vdev_t *vd)
sizeof (zio_t), offsetof(struct zio, io_queue_node));
}
- vq->vq_lastoffset = 0;
+ vq->vq_last_offset = 0;
}
void
@@ -699,9 +699,8 @@ again:
*/
tree = vdev_queue_class_tree(vq, p);
vq->vq_io_search.io_timestamp = 0;
- vq->vq_io_search.io_offset = vq->vq_last_offset + 1;
- VERIFY3P(avl_find(tree, &vq->vq_io_search,
- &idx), ==, NULL);
+ vq->vq_io_search.io_offset = vq->vq_last_offset - 1;
+ VERIFY3P(avl_find(tree, &vq->vq_io_search, &idx), ==, NULL);
zio = avl_nearest(tree, idx, AVL_AFTER);
if (zio == NULL)
zio = avl_first(tree);
@@ -728,7 +727,7 @@ again:
}
vdev_queue_pending_add(vq, zio);
- vq->vq_last_offset = zio->io_offset;
+ vq->vq_last_offset = zio->io_offset + zio->io_size;
return (zio);
}
@@ -806,7 +805,7 @@ vdev_queue_io_done(zio_t *zio)
}
/*
- * As these three methods are only used for load calculations we're not
+ * As these two methods are only used for load calculations we're not
* concerned if we get an incorrect value on 32bit platforms due to lack of
* vq_lock mutex use here, instead we prefer to keep it lock free for
* performance.
@@ -818,15 +817,9 @@ vdev_queue_length(vdev_t *vd)
}
uint64_t
-vdev_queue_lastoffset(vdev_t *vd)
+vdev_queue_last_offset(vdev_t *vd)
{
- return (vd->vdev_queue.vq_lastoffset);
-}
-
-void
-vdev_queue_register_lastoffset(vdev_t *vd, zio_t *zio)
-{
- vd->vdev_queue.vq_lastoffset = zio->io_offset + zio->io_size;
+ return (vd->vdev_queue.vq_last_offset);
}
#if defined(_KERNEL) && defined(HAVE_SPL)