1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#include <sys/zfs_context.h>
27#include <sys/spa.h>
28#include <sys/vdev_impl.h>
29#include <sys/zio.h>
30#include <sys/avl.h>
31
32/*
33 * These tunables are for performance analysis.
34 */
35/*
36 * zfs_vdev_max_pending is the maximum number of i/os concurrently
37 * pending to each device. zfs_vdev_min_pending is the initial number
38 * of i/os pending to each device (before it starts ramping up to
39 * max_pending).
40 */
41int zfs_vdev_max_pending = 35;
42int zfs_vdev_min_pending = 4;
43
44/* deadline = pri + (LBOLT >> time_shift) */
45int zfs_vdev_time_shift = 6;
46
47/* exponential I/O issue ramp-up rate */
48int zfs_vdev_ramp_rate = 2;
49
50/*
51 * i/os will be aggregated into a single large i/o up to
52 * zfs_vdev_aggregation_limit bytes long.
53 */
54int zfs_vdev_aggregation_limit = SPA_MAXBLOCKSIZE;
55
56SYSCTL_DECL(_vfs_zfs_vdev);
57TUNABLE_INT("vfs.zfs.vdev.max_pending", &zfs_vdev_max_pending);
58SYSCTL_INT(_vfs_zfs_vdev, OID_AUTO, max_pending, CTLFLAG_RDTUN,
59 &zfs_vdev_max_pending, 0, "Maximum I/O requests pending on each device");
60TUNABLE_INT("vfs.zfs.vdev.min_pending", &zfs_vdev_min_pending);
61SYSCTL_INT(_vfs_zfs_vdev, OID_AUTO, min_pending, CTLFLAG_RDTUN,
62 &zfs_vdev_min_pending, 0,
63 "Initial number of I/O requests pending to each device");
64TUNABLE_INT("vfs.zfs.vdev.time_shift", &zfs_vdev_time_shift);
65SYSCTL_INT(_vfs_zfs_vdev, OID_AUTO, time_shift, CTLFLAG_RDTUN,
66 &zfs_vdev_time_shift, 0, "Used for calculating I/O request deadline");
67TUNABLE_INT("vfs.zfs.vdev.ramp_rate", &zfs_vdev_ramp_rate);
68SYSCTL_INT(_vfs_zfs_vdev, OID_AUTO, ramp_rate, CTLFLAG_RDTUN,
69 &zfs_vdev_ramp_rate, 0, "Exponential I/O issue ramp-up rate");
70TUNABLE_INT("vfs.zfs.vdev.aggregation_limit", &zfs_vdev_aggregation_limit);
71SYSCTL_INT(_vfs_zfs_vdev, OID_AUTO, aggregation_limit, CTLFLAG_RDTUN,
72 &zfs_vdev_aggregation_limit, 0,
73 "I/O requests are aggregated up to this size");
74
75/*
76 * Virtual device vector for disk I/O scheduling.
77 */
78int
79vdev_queue_deadline_compare(const void *x1, const void *x2)
80{
81 const zio_t *z1 = x1;
82 const zio_t *z2 = x2;
83
84 if (z1->io_deadline < z2->io_deadline)
85 return (-1);
86 if (z1->io_deadline > z2->io_deadline)
87 return (1);
88
89 if (z1->io_offset < z2->io_offset)
90 return (-1);
91 if (z1->io_offset > z2->io_offset)
92 return (1);
93
94 if (z1 < z2)
95 return (-1);
96 if (z1 > z2)
97 return (1);
98
99 return (0);
100}
101
102int
103vdev_queue_offset_compare(const void *x1, const void *x2)
104{
105 const zio_t *z1 = x1;
106 const zio_t *z2 = x2;
107
108 if (z1->io_offset < z2->io_offset)
109 return (-1);
110 if (z1->io_offset > z2->io_offset)
111 return (1);
112
113 if (z1 < z2)
114 return (-1);
115 if (z1 > z2)
116 return (1);
117
118 return (0);
119}
120
121void
122vdev_queue_init(vdev_t *vd)
123{
124 vdev_queue_t *vq = &vd->vdev_queue;
125
126 mutex_init(&vq->vq_lock, NULL, MUTEX_DEFAULT, NULL);
127
128 avl_create(&vq->vq_deadline_tree, vdev_queue_deadline_compare,
129 sizeof (zio_t), offsetof(struct zio, io_deadline_node));
130
131 avl_create(&vq->vq_read_tree, vdev_queue_offset_compare,
132 sizeof (zio_t), offsetof(struct zio, io_offset_node));
133
134 avl_create(&vq->vq_write_tree, vdev_queue_offset_compare,
135 sizeof (zio_t), offsetof(struct zio, io_offset_node));
136
137 avl_create(&vq->vq_pending_tree, vdev_queue_offset_compare,
138 sizeof (zio_t), offsetof(struct zio, io_offset_node));
139}
140
141void
142vdev_queue_fini(vdev_t *vd)
143{
144 vdev_queue_t *vq = &vd->vdev_queue;
145
146 avl_destroy(&vq->vq_deadline_tree);
147 avl_destroy(&vq->vq_read_tree);
148 avl_destroy(&vq->vq_write_tree);
149 avl_destroy(&vq->vq_pending_tree);
150
151 mutex_destroy(&vq->vq_lock);
152}
153
154static void
155vdev_queue_io_add(vdev_queue_t *vq, zio_t *zio)
156{
157 avl_add(&vq->vq_deadline_tree, zio);
158 avl_add(zio->io_vdev_tree, zio);
159}
160
161static void
162vdev_queue_io_remove(vdev_queue_t *vq, zio_t *zio)
163{
164 avl_remove(&vq->vq_deadline_tree, zio);
165 avl_remove(zio->io_vdev_tree, zio);
166}
167
168static void
169vdev_queue_agg_io_done(zio_t *aio)
170{
171 zio_t *dio;
172 uint64_t offset = 0;
173
174 while ((dio = aio->io_delegate_list) != NULL) {
175 if (aio->io_type == ZIO_TYPE_READ)
176 bcopy((char *)aio->io_data + offset, dio->io_data,
177 dio->io_size);
178 offset += dio->io_size;
179 aio->io_delegate_list = dio->io_delegate_next;
180 dio->io_delegate_next = NULL;
181 dio->io_error = aio->io_error;
182 zio_execute(dio);
183 }
184 ASSERT3U(offset, ==, aio->io_size);
185
186 zio_buf_free(aio->io_data, aio->io_size);
187}
188
189#define IS_ADJACENT(io, nio) \
190 ((io)->io_offset + (io)->io_size == (nio)->io_offset)
191
192static zio_t *
193vdev_queue_io_to_issue(vdev_queue_t *vq, uint64_t pending_limit)
194{
195 zio_t *fio, *lio, *aio, *dio;
196 avl_tree_t *tree;
197 uint64_t size;
198
199 ASSERT(MUTEX_HELD(&vq->vq_lock));
200
201 if (avl_numnodes(&vq->vq_pending_tree) >= pending_limit ||
202 avl_numnodes(&vq->vq_deadline_tree) == 0)
203 return (NULL);
204
205 fio = lio = avl_first(&vq->vq_deadline_tree);
206
207 tree = fio->io_vdev_tree;
208 size = fio->io_size;
209
210 while ((dio = AVL_PREV(tree, fio)) != NULL && IS_ADJACENT(dio, fio) &&
211 !((dio->io_flags | fio->io_flags) & ZIO_FLAG_DONT_AGGREGATE) &&
212 size + dio->io_size <= zfs_vdev_aggregation_limit) {
213 dio->io_delegate_next = fio;
214 fio = dio;
215 size += dio->io_size;
216 }
217
218 while ((dio = AVL_NEXT(tree, lio)) != NULL && IS_ADJACENT(lio, dio) &&
219 !((lio->io_flags | dio->io_flags) & ZIO_FLAG_DONT_AGGREGATE) &&
220 size + dio->io_size <= zfs_vdev_aggregation_limit) {
221 lio->io_delegate_next = dio;
222 lio = dio;
223 size += dio->io_size;
224 }
225
226 if (fio != lio) {
227 char *buf = zio_buf_alloc(size);
228 uint64_t offset = 0;
229
230 ASSERT(size <= zfs_vdev_aggregation_limit);
231
232 aio = zio_vdev_delegated_io(fio->io_vd, fio->io_offset,
233 buf, size, fio->io_type, ZIO_PRIORITY_NOW,
234 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_QUEUE,
235 vdev_queue_agg_io_done, NULL);
236
237 aio->io_delegate_list = fio;
238
239 for (dio = fio; dio != NULL; dio = dio->io_delegate_next) {
240 ASSERT(dio->io_type == aio->io_type);
241 ASSERT(dio->io_vdev_tree == tree);
242 if (dio->io_type == ZIO_TYPE_WRITE)
243 bcopy(dio->io_data, buf + offset, dio->io_size);
244 offset += dio->io_size;
245 vdev_queue_io_remove(vq, dio);
246 zio_vdev_io_bypass(dio);
247 }
248
249 ASSERT(offset == size);
250
251 avl_add(&vq->vq_pending_tree, aio);
252
253 return (aio);
254 }
255
256 ASSERT(fio->io_vdev_tree == tree);
257 vdev_queue_io_remove(vq, fio);
258
259 avl_add(&vq->vq_pending_tree, fio);
260
261 return (fio);
262}
263
264zio_t *
265vdev_queue_io(zio_t *zio)
266{
267 vdev_queue_t *vq = &zio->io_vd->vdev_queue;
268 zio_t *nio;
269
270 ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
271
272 if (zio->io_flags & ZIO_FLAG_DONT_QUEUE)
273 return (zio);
274
275 zio->io_flags |= ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_QUEUE;
276
277 if (zio->io_type == ZIO_TYPE_READ)
278 zio->io_vdev_tree = &vq->vq_read_tree;
279 else
280 zio->io_vdev_tree = &vq->vq_write_tree;
281
282 mutex_enter(&vq->vq_lock);
283
284 zio->io_deadline = (lbolt64 >> zfs_vdev_time_shift) + zio->io_priority;
285
286 vdev_queue_io_add(vq, zio);
287
288 nio = vdev_queue_io_to_issue(vq, zfs_vdev_min_pending);
289
290 mutex_exit(&vq->vq_lock);
291
292 if (nio == NULL)
293 return (NULL);
294
295 if (nio->io_done == vdev_queue_agg_io_done) {
296 zio_nowait(nio);
297 return (NULL);
298 }
299
300 return (nio);
301}
302
303void
304vdev_queue_io_done(zio_t *zio)
305{
306 vdev_queue_t *vq = &zio->io_vd->vdev_queue;
307
308 mutex_enter(&vq->vq_lock);
309
310 avl_remove(&vq->vq_pending_tree, zio);
311
312 for (int i = 0; i < zfs_vdev_ramp_rate; i++) {
313 zio_t *nio = vdev_queue_io_to_issue(vq, zfs_vdev_max_pending);
314 if (nio == NULL)
315 break;
316 mutex_exit(&vq->vq_lock);
317 if (nio->io_done == vdev_queue_agg_io_done) {
318 zio_nowait(nio);
319 } else {
320 zio_vdev_io_reissue(nio);
321 zio_execute(nio);
322 }
323 mutex_enter(&vq->vq_lock);
324 }
325
326 mutex_exit(&vq->vq_lock);
327}
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#include <sys/zfs_context.h>
27#include <sys/spa.h>
28#include <sys/vdev_impl.h>
29#include <sys/zio.h>
30#include <sys/avl.h>
31
32/*
33 * These tunables are for performance analysis.
34 */
35/*
36 * zfs_vdev_max_pending is the maximum number of i/os concurrently
37 * pending to each device. zfs_vdev_min_pending is the initial number
38 * of i/os pending to each device (before it starts ramping up to
39 * max_pending).
40 */
41int zfs_vdev_max_pending = 35;
42int zfs_vdev_min_pending = 4;
43
44/* deadline = pri + (LBOLT >> time_shift) */
45int zfs_vdev_time_shift = 6;
46
47/* exponential I/O issue ramp-up rate */
48int zfs_vdev_ramp_rate = 2;
49
50/*
51 * i/os will be aggregated into a single large i/o up to
52 * zfs_vdev_aggregation_limit bytes long.
53 */
54int zfs_vdev_aggregation_limit = SPA_MAXBLOCKSIZE;
55
56SYSCTL_DECL(_vfs_zfs_vdev);
57TUNABLE_INT("vfs.zfs.vdev.max_pending", &zfs_vdev_max_pending);
58SYSCTL_INT(_vfs_zfs_vdev, OID_AUTO, max_pending, CTLFLAG_RDTUN,
59 &zfs_vdev_max_pending, 0, "Maximum I/O requests pending on each device");
60TUNABLE_INT("vfs.zfs.vdev.min_pending", &zfs_vdev_min_pending);
61SYSCTL_INT(_vfs_zfs_vdev, OID_AUTO, min_pending, CTLFLAG_RDTUN,
62 &zfs_vdev_min_pending, 0,
63 "Initial number of I/O requests pending to each device");
64TUNABLE_INT("vfs.zfs.vdev.time_shift", &zfs_vdev_time_shift);
65SYSCTL_INT(_vfs_zfs_vdev, OID_AUTO, time_shift, CTLFLAG_RDTUN,
66 &zfs_vdev_time_shift, 0, "Used for calculating I/O request deadline");
67TUNABLE_INT("vfs.zfs.vdev.ramp_rate", &zfs_vdev_ramp_rate);
68SYSCTL_INT(_vfs_zfs_vdev, OID_AUTO, ramp_rate, CTLFLAG_RDTUN,
69 &zfs_vdev_ramp_rate, 0, "Exponential I/O issue ramp-up rate");
70TUNABLE_INT("vfs.zfs.vdev.aggregation_limit", &zfs_vdev_aggregation_limit);
71SYSCTL_INT(_vfs_zfs_vdev, OID_AUTO, aggregation_limit, CTLFLAG_RDTUN,
72 &zfs_vdev_aggregation_limit, 0,
73 "I/O requests are aggregated up to this size");
74
75/*
76 * Virtual device vector for disk I/O scheduling.
77 */
78int
79vdev_queue_deadline_compare(const void *x1, const void *x2)
80{
81 const zio_t *z1 = x1;
82 const zio_t *z2 = x2;
83
84 if (z1->io_deadline < z2->io_deadline)
85 return (-1);
86 if (z1->io_deadline > z2->io_deadline)
87 return (1);
88
89 if (z1->io_offset < z2->io_offset)
90 return (-1);
91 if (z1->io_offset > z2->io_offset)
92 return (1);
93
94 if (z1 < z2)
95 return (-1);
96 if (z1 > z2)
97 return (1);
98
99 return (0);
100}
101
102int
103vdev_queue_offset_compare(const void *x1, const void *x2)
104{
105 const zio_t *z1 = x1;
106 const zio_t *z2 = x2;
107
108 if (z1->io_offset < z2->io_offset)
109 return (-1);
110 if (z1->io_offset > z2->io_offset)
111 return (1);
112
113 if (z1 < z2)
114 return (-1);
115 if (z1 > z2)
116 return (1);
117
118 return (0);
119}
120
121void
122vdev_queue_init(vdev_t *vd)
123{
124 vdev_queue_t *vq = &vd->vdev_queue;
125
126 mutex_init(&vq->vq_lock, NULL, MUTEX_DEFAULT, NULL);
127
128 avl_create(&vq->vq_deadline_tree, vdev_queue_deadline_compare,
129 sizeof (zio_t), offsetof(struct zio, io_deadline_node));
130
131 avl_create(&vq->vq_read_tree, vdev_queue_offset_compare,
132 sizeof (zio_t), offsetof(struct zio, io_offset_node));
133
134 avl_create(&vq->vq_write_tree, vdev_queue_offset_compare,
135 sizeof (zio_t), offsetof(struct zio, io_offset_node));
136
137 avl_create(&vq->vq_pending_tree, vdev_queue_offset_compare,
138 sizeof (zio_t), offsetof(struct zio, io_offset_node));
139}
140
141void
142vdev_queue_fini(vdev_t *vd)
143{
144 vdev_queue_t *vq = &vd->vdev_queue;
145
146 avl_destroy(&vq->vq_deadline_tree);
147 avl_destroy(&vq->vq_read_tree);
148 avl_destroy(&vq->vq_write_tree);
149 avl_destroy(&vq->vq_pending_tree);
150
151 mutex_destroy(&vq->vq_lock);
152}
153
154static void
155vdev_queue_io_add(vdev_queue_t *vq, zio_t *zio)
156{
157 avl_add(&vq->vq_deadline_tree, zio);
158 avl_add(zio->io_vdev_tree, zio);
159}
160
161static void
162vdev_queue_io_remove(vdev_queue_t *vq, zio_t *zio)
163{
164 avl_remove(&vq->vq_deadline_tree, zio);
165 avl_remove(zio->io_vdev_tree, zio);
166}
167
168static void
169vdev_queue_agg_io_done(zio_t *aio)
170{
171 zio_t *dio;
172 uint64_t offset = 0;
173
174 while ((dio = aio->io_delegate_list) != NULL) {
175 if (aio->io_type == ZIO_TYPE_READ)
176 bcopy((char *)aio->io_data + offset, dio->io_data,
177 dio->io_size);
178 offset += dio->io_size;
179 aio->io_delegate_list = dio->io_delegate_next;
180 dio->io_delegate_next = NULL;
181 dio->io_error = aio->io_error;
182 zio_execute(dio);
183 }
184 ASSERT3U(offset, ==, aio->io_size);
185
186 zio_buf_free(aio->io_data, aio->io_size);
187}
188
189#define IS_ADJACENT(io, nio) \
190 ((io)->io_offset + (io)->io_size == (nio)->io_offset)
191
192static zio_t *
193vdev_queue_io_to_issue(vdev_queue_t *vq, uint64_t pending_limit)
194{
195 zio_t *fio, *lio, *aio, *dio;
196 avl_tree_t *tree;
197 uint64_t size;
198
199 ASSERT(MUTEX_HELD(&vq->vq_lock));
200
201 if (avl_numnodes(&vq->vq_pending_tree) >= pending_limit ||
202 avl_numnodes(&vq->vq_deadline_tree) == 0)
203 return (NULL);
204
205 fio = lio = avl_first(&vq->vq_deadline_tree);
206
207 tree = fio->io_vdev_tree;
208 size = fio->io_size;
209
210 while ((dio = AVL_PREV(tree, fio)) != NULL && IS_ADJACENT(dio, fio) &&
211 !((dio->io_flags | fio->io_flags) & ZIO_FLAG_DONT_AGGREGATE) &&
212 size + dio->io_size <= zfs_vdev_aggregation_limit) {
213 dio->io_delegate_next = fio;
214 fio = dio;
215 size += dio->io_size;
216 }
217
218 while ((dio = AVL_NEXT(tree, lio)) != NULL && IS_ADJACENT(lio, dio) &&
219 !((lio->io_flags | dio->io_flags) & ZIO_FLAG_DONT_AGGREGATE) &&
220 size + dio->io_size <= zfs_vdev_aggregation_limit) {
221 lio->io_delegate_next = dio;
222 lio = dio;
223 size += dio->io_size;
224 }
225
226 if (fio != lio) {
227 char *buf = zio_buf_alloc(size);
228 uint64_t offset = 0;
229
230 ASSERT(size <= zfs_vdev_aggregation_limit);
231
232 aio = zio_vdev_delegated_io(fio->io_vd, fio->io_offset,
233 buf, size, fio->io_type, ZIO_PRIORITY_NOW,
234 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_QUEUE,
235 vdev_queue_agg_io_done, NULL);
236
237 aio->io_delegate_list = fio;
238
239 for (dio = fio; dio != NULL; dio = dio->io_delegate_next) {
240 ASSERT(dio->io_type == aio->io_type);
241 ASSERT(dio->io_vdev_tree == tree);
242 if (dio->io_type == ZIO_TYPE_WRITE)
243 bcopy(dio->io_data, buf + offset, dio->io_size);
244 offset += dio->io_size;
245 vdev_queue_io_remove(vq, dio);
246 zio_vdev_io_bypass(dio);
247 }
248
249 ASSERT(offset == size);
250
251 avl_add(&vq->vq_pending_tree, aio);
252
253 return (aio);
254 }
255
256 ASSERT(fio->io_vdev_tree == tree);
257 vdev_queue_io_remove(vq, fio);
258
259 avl_add(&vq->vq_pending_tree, fio);
260
261 return (fio);
262}
263
264zio_t *
265vdev_queue_io(zio_t *zio)
266{
267 vdev_queue_t *vq = &zio->io_vd->vdev_queue;
268 zio_t *nio;
269
270 ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
271
272 if (zio->io_flags & ZIO_FLAG_DONT_QUEUE)
273 return (zio);
274
275 zio->io_flags |= ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_QUEUE;
276
277 if (zio->io_type == ZIO_TYPE_READ)
278 zio->io_vdev_tree = &vq->vq_read_tree;
279 else
280 zio->io_vdev_tree = &vq->vq_write_tree;
281
282 mutex_enter(&vq->vq_lock);
283
284 zio->io_deadline = (lbolt64 >> zfs_vdev_time_shift) + zio->io_priority;
285
286 vdev_queue_io_add(vq, zio);
287
288 nio = vdev_queue_io_to_issue(vq, zfs_vdev_min_pending);
289
290 mutex_exit(&vq->vq_lock);
291
292 if (nio == NULL)
293 return (NULL);
294
295 if (nio->io_done == vdev_queue_agg_io_done) {
296 zio_nowait(nio);
297 return (NULL);
298 }
299
300 return (nio);
301}
302
303void
304vdev_queue_io_done(zio_t *zio)
305{
306 vdev_queue_t *vq = &zio->io_vd->vdev_queue;
307
308 mutex_enter(&vq->vq_lock);
309
310 avl_remove(&vq->vq_pending_tree, zio);
311
312 for (int i = 0; i < zfs_vdev_ramp_rate; i++) {
313 zio_t *nio = vdev_queue_io_to_issue(vq, zfs_vdev_max_pending);
314 if (nio == NULL)
315 break;
316 mutex_exit(&vq->vq_lock);
317 if (nio->io_done == vdev_queue_agg_io_done) {
318 zio_nowait(nio);
319 } else {
320 zio_vdev_io_reissue(nio);
321 zio_execute(nio);
322 }
323 mutex_enter(&vq->vq_lock);
324 }
325
326 mutex_exit(&vq->vq_lock);
327}