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authorBrian Behlendorf <[email protected]>2008-12-11 11:08:09 -0800
committerBrian Behlendorf <[email protected]>2008-12-11 11:08:09 -0800
commit172bb4bd5e4afef721dd4d2972d8680d983f144b (patch)
tree18ab1e97e5e409150066c529b5a981ecf600ef80 /module/zfs/vdev_queue.c
parent9e8b1e836caa454586797f771a7ad1817ebae315 (diff)
Move the world out of /zfs/ and seperate out module build tree
Diffstat (limited to 'module/zfs/vdev_queue.c')
-rw-r--r--module/zfs/vdev_queue.c308
1 files changed, 308 insertions, 0 deletions
diff --git a/module/zfs/vdev_queue.c b/module/zfs/vdev_queue.c
new file mode 100644
index 000000000..46fca0e3b
--- /dev/null
+++ b/module/zfs/vdev_queue.c
@@ -0,0 +1,308 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#include <sys/zfs_context.h>
+#include <sys/spa.h>
+#include <sys/vdev_impl.h>
+#include <sys/zio.h>
+#include <sys/avl.h>
+
+/*
+ * These tunables are for performance analysis.
+ */
+/*
+ * zfs_vdev_max_pending is the maximum number of i/os concurrently
+ * pending to each device. zfs_vdev_min_pending is the initial number
+ * of i/os pending to each device (before it starts ramping up to
+ * max_pending).
+ */
+int zfs_vdev_max_pending = 35;
+int zfs_vdev_min_pending = 4;
+
+/* deadline = pri + (lbolt >> time_shift) */
+int zfs_vdev_time_shift = 6;
+
+/* exponential I/O issue ramp-up rate */
+int zfs_vdev_ramp_rate = 2;
+
+/*
+ * i/os will be aggregated into a single large i/o up to
+ * zfs_vdev_aggregation_limit bytes long.
+ */
+int zfs_vdev_aggregation_limit = SPA_MAXBLOCKSIZE;
+
+/*
+ * Virtual device vector for disk I/O scheduling.
+ */
+int
+vdev_queue_deadline_compare(const void *x1, const void *x2)
+{
+ const zio_t *z1 = x1;
+ const zio_t *z2 = x2;
+
+ if (z1->io_deadline < z2->io_deadline)
+ return (-1);
+ if (z1->io_deadline > z2->io_deadline)
+ return (1);
+
+ if (z1->io_offset < z2->io_offset)
+ return (-1);
+ if (z1->io_offset > z2->io_offset)
+ return (1);
+
+ if (z1 < z2)
+ return (-1);
+ if (z1 > z2)
+ return (1);
+
+ return (0);
+}
+
+int
+vdev_queue_offset_compare(const void *x1, const void *x2)
+{
+ const zio_t *z1 = x1;
+ const zio_t *z2 = x2;
+
+ if (z1->io_offset < z2->io_offset)
+ return (-1);
+ if (z1->io_offset > z2->io_offset)
+ return (1);
+
+ if (z1 < z2)
+ return (-1);
+ if (z1 > z2)
+ return (1);
+
+ return (0);
+}
+
+void
+vdev_queue_init(vdev_t *vd)
+{
+ vdev_queue_t *vq = &vd->vdev_queue;
+
+ mutex_init(&vq->vq_lock, NULL, MUTEX_DEFAULT, NULL);
+
+ avl_create(&vq->vq_deadline_tree, vdev_queue_deadline_compare,
+ sizeof (zio_t), offsetof(struct zio, io_deadline_node));
+
+ avl_create(&vq->vq_read_tree, vdev_queue_offset_compare,
+ sizeof (zio_t), offsetof(struct zio, io_offset_node));
+
+ avl_create(&vq->vq_write_tree, vdev_queue_offset_compare,
+ sizeof (zio_t), offsetof(struct zio, io_offset_node));
+
+ avl_create(&vq->vq_pending_tree, vdev_queue_offset_compare,
+ sizeof (zio_t), offsetof(struct zio, io_offset_node));
+}
+
+void
+vdev_queue_fini(vdev_t *vd)
+{
+ vdev_queue_t *vq = &vd->vdev_queue;
+
+ avl_destroy(&vq->vq_deadline_tree);
+ avl_destroy(&vq->vq_read_tree);
+ avl_destroy(&vq->vq_write_tree);
+ avl_destroy(&vq->vq_pending_tree);
+
+ mutex_destroy(&vq->vq_lock);
+}
+
+static void
+vdev_queue_io_add(vdev_queue_t *vq, zio_t *zio)
+{
+ avl_add(&vq->vq_deadline_tree, zio);
+ avl_add(zio->io_vdev_tree, zio);
+}
+
+static void
+vdev_queue_io_remove(vdev_queue_t *vq, zio_t *zio)
+{
+ avl_remove(&vq->vq_deadline_tree, zio);
+ avl_remove(zio->io_vdev_tree, zio);
+}
+
+static void
+vdev_queue_agg_io_done(zio_t *aio)
+{
+ zio_t *dio;
+ uint64_t offset = 0;
+
+ while ((dio = aio->io_delegate_list) != NULL) {
+ if (aio->io_type == ZIO_TYPE_READ)
+ bcopy((char *)aio->io_data + offset, dio->io_data,
+ dio->io_size);
+ offset += dio->io_size;
+ aio->io_delegate_list = dio->io_delegate_next;
+ dio->io_delegate_next = NULL;
+ dio->io_error = aio->io_error;
+ zio_execute(dio);
+ }
+ ASSERT3U(offset, ==, aio->io_size);
+
+ zio_buf_free(aio->io_data, aio->io_size);
+}
+
+#define IS_ADJACENT(io, nio) \
+ ((io)->io_offset + (io)->io_size == (nio)->io_offset)
+
+static zio_t *
+vdev_queue_io_to_issue(vdev_queue_t *vq, uint64_t pending_limit)
+{
+ zio_t *fio, *lio, *aio, *dio;
+ avl_tree_t *tree;
+ uint64_t size;
+
+ ASSERT(MUTEX_HELD(&vq->vq_lock));
+
+ if (avl_numnodes(&vq->vq_pending_tree) >= pending_limit ||
+ avl_numnodes(&vq->vq_deadline_tree) == 0)
+ return (NULL);
+
+ fio = lio = avl_first(&vq->vq_deadline_tree);
+
+ tree = fio->io_vdev_tree;
+ size = fio->io_size;
+
+ while ((dio = AVL_PREV(tree, fio)) != NULL && IS_ADJACENT(dio, fio) &&
+ !((dio->io_flags | fio->io_flags) & ZIO_FLAG_DONT_AGGREGATE) &&
+ size + dio->io_size <= zfs_vdev_aggregation_limit) {
+ dio->io_delegate_next = fio;
+ fio = dio;
+ size += dio->io_size;
+ }
+
+ while ((dio = AVL_NEXT(tree, lio)) != NULL && IS_ADJACENT(lio, dio) &&
+ !((lio->io_flags | dio->io_flags) & ZIO_FLAG_DONT_AGGREGATE) &&
+ size + dio->io_size <= zfs_vdev_aggregation_limit) {
+ lio->io_delegate_next = dio;
+ lio = dio;
+ size += dio->io_size;
+ }
+
+ if (fio != lio) {
+ char *buf = zio_buf_alloc(size);
+ uint64_t offset = 0;
+
+ ASSERT(size <= zfs_vdev_aggregation_limit);
+
+ aio = zio_vdev_delegated_io(fio->io_vd, fio->io_offset,
+ buf, size, fio->io_type, ZIO_PRIORITY_NOW,
+ ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_QUEUE,
+ vdev_queue_agg_io_done, NULL);
+
+ aio->io_delegate_list = fio;
+
+ for (dio = fio; dio != NULL; dio = dio->io_delegate_next) {
+ ASSERT(dio->io_type == aio->io_type);
+ ASSERT(dio->io_vdev_tree == tree);
+ if (dio->io_type == ZIO_TYPE_WRITE)
+ bcopy(dio->io_data, buf + offset, dio->io_size);
+ offset += dio->io_size;
+ vdev_queue_io_remove(vq, dio);
+ zio_vdev_io_bypass(dio);
+ }
+
+ ASSERT(offset == size);
+
+ avl_add(&vq->vq_pending_tree, aio);
+
+ return (aio);
+ }
+
+ ASSERT(fio->io_vdev_tree == tree);
+ vdev_queue_io_remove(vq, fio);
+
+ avl_add(&vq->vq_pending_tree, fio);
+
+ return (fio);
+}
+
+zio_t *
+vdev_queue_io(zio_t *zio)
+{
+ vdev_queue_t *vq = &zio->io_vd->vdev_queue;
+ zio_t *nio;
+
+ ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
+
+ if (zio->io_flags & ZIO_FLAG_DONT_QUEUE)
+ return (zio);
+
+ zio->io_flags |= ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_QUEUE;
+
+ if (zio->io_type == ZIO_TYPE_READ)
+ zio->io_vdev_tree = &vq->vq_read_tree;
+ else
+ zio->io_vdev_tree = &vq->vq_write_tree;
+
+ mutex_enter(&vq->vq_lock);
+
+ zio->io_deadline = (lbolt64 >> zfs_vdev_time_shift) + zio->io_priority;
+
+ vdev_queue_io_add(vq, zio);
+
+ nio = vdev_queue_io_to_issue(vq, zfs_vdev_min_pending);
+
+ mutex_exit(&vq->vq_lock);
+
+ if (nio == NULL)
+ return (NULL);
+
+ if (nio->io_done == vdev_queue_agg_io_done) {
+ zio_nowait(nio);
+ return (NULL);
+ }
+
+ return (nio);
+}
+
+void
+vdev_queue_io_done(zio_t *zio)
+{
+ vdev_queue_t *vq = &zio->io_vd->vdev_queue;
+
+ mutex_enter(&vq->vq_lock);
+
+ avl_remove(&vq->vq_pending_tree, zio);
+
+ for (int i = 0; i < zfs_vdev_ramp_rate; i++) {
+ zio_t *nio = vdev_queue_io_to_issue(vq, zfs_vdev_max_pending);
+ if (nio == NULL)
+ break;
+ mutex_exit(&vq->vq_lock);
+ if (nio->io_done == vdev_queue_agg_io_done) {
+ zio_nowait(nio);
+ } else {
+ zio_vdev_io_reissue(nio);
+ zio_execute(nio);
+ }
+ mutex_enter(&vq->vq_lock);
+ }
+
+ mutex_exit(&vq->vq_lock);
+}