vdev_queue.c revision 168404
1168404Spjd/* 2168404Spjd * CDDL HEADER START 3168404Spjd * 4168404Spjd * The contents of this file are subject to the terms of the 5168404Spjd * Common Development and Distribution License (the "License"). 6168404Spjd * You may not use this file except in compliance with the License. 7168404Spjd * 8168404Spjd * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9168404Spjd * or http://www.opensolaris.org/os/licensing. 10168404Spjd * See the License for the specific language governing permissions 11168404Spjd * and limitations under the License. 12168404Spjd * 13168404Spjd * When distributing Covered Code, include this CDDL HEADER in each 14168404Spjd * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15168404Spjd * If applicable, add the following below this CDDL HEADER, with the 16168404Spjd * fields enclosed by brackets "[]" replaced with your own identifying 17168404Spjd * information: Portions Copyright [yyyy] [name of copyright owner] 18168404Spjd * 19168404Spjd * CDDL HEADER END 20168404Spjd */ 21168404Spjd/* 22168404Spjd * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 23168404Spjd * Use is subject to license terms. 24168404Spjd */ 25168404Spjd 26168404Spjd#pragma ident "%Z%%M% %I% %E% SMI" 27168404Spjd 28168404Spjd#include <sys/zfs_context.h> 29168404Spjd#include <sys/spa.h> 30168404Spjd#include <sys/vdev_impl.h> 31168404Spjd#include <sys/zio.h> 32168404Spjd#include <sys/avl.h> 33168404Spjd 34168404Spjd/* 35168404Spjd * These tunables are for performance analysis. 36168404Spjd */ 37168404Spjd/* 38168404Spjd * zfs_vdev_max_pending is the maximum number of i/os concurrently 39168404Spjd * pending to each device. zfs_vdev_min_pending is the initial number 40168404Spjd * of i/os pending to each device (before it starts ramping up to 41168404Spjd * max_pending). 42168404Spjd */ 43168404Spjdint zfs_vdev_max_pending = 35; 44168404Spjdint zfs_vdev_min_pending = 4; 45168404Spjd 46168404Spjd/* deadline = pri + (lbolt >> time_shift) */ 47168404Spjdint zfs_vdev_time_shift = 6; 48168404Spjd 49168404Spjd/* exponential I/O issue ramp-up rate */ 50168404Spjdint zfs_vdev_ramp_rate = 2; 51168404Spjd 52168404Spjd/* 53168404Spjd * i/os will be aggregated into a single large i/o up to 54168404Spjd * zfs_vdev_aggregation_limit bytes long. 55168404Spjd */ 56168404Spjdint zfs_vdev_aggregation_limit = SPA_MAXBLOCKSIZE; 57168404Spjd 58168404Spjd/* 59168404Spjd * Virtual device vector for disk I/O scheduling. 60168404Spjd */ 61168404Spjdint 62168404Spjdvdev_queue_deadline_compare(const void *x1, const void *x2) 63168404Spjd{ 64168404Spjd const zio_t *z1 = x1; 65168404Spjd const zio_t *z2 = x2; 66168404Spjd 67168404Spjd if (z1->io_deadline < z2->io_deadline) 68168404Spjd return (-1); 69168404Spjd if (z1->io_deadline > z2->io_deadline) 70168404Spjd return (1); 71168404Spjd 72168404Spjd if (z1->io_offset < z2->io_offset) 73168404Spjd return (-1); 74168404Spjd if (z1->io_offset > z2->io_offset) 75168404Spjd return (1); 76168404Spjd 77168404Spjd if (z1 < z2) 78168404Spjd return (-1); 79168404Spjd if (z1 > z2) 80168404Spjd return (1); 81168404Spjd 82168404Spjd return (0); 83168404Spjd} 84168404Spjd 85168404Spjdint 86168404Spjdvdev_queue_offset_compare(const void *x1, const void *x2) 87168404Spjd{ 88168404Spjd const zio_t *z1 = x1; 89168404Spjd const zio_t *z2 = x2; 90168404Spjd 91168404Spjd if (z1->io_offset < z2->io_offset) 92168404Spjd return (-1); 93168404Spjd if (z1->io_offset > z2->io_offset) 94168404Spjd return (1); 95168404Spjd 96168404Spjd if (z1 < z2) 97168404Spjd return (-1); 98168404Spjd if (z1 > z2) 99168404Spjd return (1); 100168404Spjd 101168404Spjd return (0); 102168404Spjd} 103168404Spjd 104168404Spjdvoid 105168404Spjdvdev_queue_init(vdev_t *vd) 106168404Spjd{ 107168404Spjd vdev_queue_t *vq = &vd->vdev_queue; 108168404Spjd 109168404Spjd mutex_init(&vq->vq_lock, NULL, MUTEX_DEFAULT, NULL); 110168404Spjd 111168404Spjd avl_create(&vq->vq_deadline_tree, vdev_queue_deadline_compare, 112168404Spjd sizeof (zio_t), offsetof(struct zio, io_deadline_node)); 113168404Spjd 114168404Spjd avl_create(&vq->vq_read_tree, vdev_queue_offset_compare, 115168404Spjd sizeof (zio_t), offsetof(struct zio, io_offset_node)); 116168404Spjd 117168404Spjd avl_create(&vq->vq_write_tree, vdev_queue_offset_compare, 118168404Spjd sizeof (zio_t), offsetof(struct zio, io_offset_node)); 119168404Spjd 120168404Spjd avl_create(&vq->vq_pending_tree, vdev_queue_offset_compare, 121168404Spjd sizeof (zio_t), offsetof(struct zio, io_offset_node)); 122168404Spjd} 123168404Spjd 124168404Spjdvoid 125168404Spjdvdev_queue_fini(vdev_t *vd) 126168404Spjd{ 127168404Spjd vdev_queue_t *vq = &vd->vdev_queue; 128168404Spjd 129168404Spjd avl_destroy(&vq->vq_deadline_tree); 130168404Spjd avl_destroy(&vq->vq_read_tree); 131168404Spjd avl_destroy(&vq->vq_write_tree); 132168404Spjd avl_destroy(&vq->vq_pending_tree); 133168404Spjd 134168404Spjd mutex_destroy(&vq->vq_lock); 135168404Spjd} 136168404Spjd 137168404Spjdstatic void 138168404Spjdvdev_queue_io_add(vdev_queue_t *vq, zio_t *zio) 139168404Spjd{ 140168404Spjd avl_add(&vq->vq_deadline_tree, zio); 141168404Spjd avl_add(zio->io_vdev_tree, zio); 142168404Spjd} 143168404Spjd 144168404Spjdstatic void 145168404Spjdvdev_queue_io_remove(vdev_queue_t *vq, zio_t *zio) 146168404Spjd{ 147168404Spjd avl_remove(&vq->vq_deadline_tree, zio); 148168404Spjd avl_remove(zio->io_vdev_tree, zio); 149168404Spjd} 150168404Spjd 151168404Spjdstatic void 152168404Spjdvdev_queue_agg_io_done(zio_t *aio) 153168404Spjd{ 154168404Spjd zio_t *dio; 155168404Spjd uint64_t offset = 0; 156168404Spjd 157168404Spjd while ((dio = aio->io_delegate_list) != NULL) { 158168404Spjd if (aio->io_type == ZIO_TYPE_READ) 159168404Spjd bcopy((char *)aio->io_data + offset, dio->io_data, 160168404Spjd dio->io_size); 161168404Spjd offset += dio->io_size; 162168404Spjd aio->io_delegate_list = dio->io_delegate_next; 163168404Spjd dio->io_delegate_next = NULL; 164168404Spjd dio->io_error = aio->io_error; 165168404Spjd zio_next_stage(dio); 166168404Spjd } 167168404Spjd ASSERT3U(offset, ==, aio->io_size); 168168404Spjd 169168404Spjd zio_buf_free(aio->io_data, aio->io_size); 170168404Spjd} 171168404Spjd 172168404Spjd#define IS_ADJACENT(io, nio) \ 173168404Spjd ((io)->io_offset + (io)->io_size == (nio)->io_offset) 174168404Spjd 175168404Spjdtypedef void zio_issue_func_t(zio_t *); 176168404Spjd 177168404Spjdstatic zio_t * 178168404Spjdvdev_queue_io_to_issue(vdev_queue_t *vq, uint64_t pending_limit, 179168404Spjd zio_issue_func_t **funcp) 180168404Spjd{ 181168404Spjd zio_t *fio, *lio, *aio, *dio; 182168404Spjd avl_tree_t *tree; 183168404Spjd uint64_t size; 184168404Spjd 185168404Spjd ASSERT(MUTEX_HELD(&vq->vq_lock)); 186168404Spjd 187168404Spjd *funcp = NULL; 188168404Spjd 189168404Spjd if (avl_numnodes(&vq->vq_pending_tree) >= pending_limit || 190168404Spjd avl_numnodes(&vq->vq_deadline_tree) == 0) 191168404Spjd return (NULL); 192168404Spjd 193168404Spjd fio = lio = avl_first(&vq->vq_deadline_tree); 194168404Spjd 195168404Spjd tree = fio->io_vdev_tree; 196168404Spjd size = fio->io_size; 197168404Spjd 198168404Spjd while ((dio = AVL_PREV(tree, fio)) != NULL && IS_ADJACENT(dio, fio) && 199168404Spjd size + dio->io_size <= zfs_vdev_aggregation_limit) { 200168404Spjd dio->io_delegate_next = fio; 201168404Spjd fio = dio; 202168404Spjd size += dio->io_size; 203168404Spjd } 204168404Spjd 205168404Spjd while ((dio = AVL_NEXT(tree, lio)) != NULL && IS_ADJACENT(lio, dio) && 206168404Spjd size + dio->io_size <= zfs_vdev_aggregation_limit) { 207168404Spjd lio->io_delegate_next = dio; 208168404Spjd lio = dio; 209168404Spjd size += dio->io_size; 210168404Spjd } 211168404Spjd 212168404Spjd if (fio != lio) { 213168404Spjd char *buf = zio_buf_alloc(size); 214168404Spjd uint64_t offset = 0; 215168404Spjd int nagg = 0; 216168404Spjd 217168404Spjd ASSERT(size <= zfs_vdev_aggregation_limit); 218168404Spjd 219168404Spjd aio = zio_vdev_child_io(fio, NULL, fio->io_vd, 220168404Spjd fio->io_offset, buf, size, fio->io_type, 221168404Spjd ZIO_PRIORITY_NOW, ZIO_FLAG_DONT_QUEUE | 222168404Spjd ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_PROPAGATE | 223168404Spjd ZIO_FLAG_NOBOOKMARK, 224168404Spjd vdev_queue_agg_io_done, NULL); 225168404Spjd 226168404Spjd aio->io_delegate_list = fio; 227168404Spjd 228168404Spjd for (dio = fio; dio != NULL; dio = dio->io_delegate_next) { 229168404Spjd ASSERT(dio->io_type == aio->io_type); 230168404Spjd ASSERT(dio->io_vdev_tree == tree); 231168404Spjd if (dio->io_type == ZIO_TYPE_WRITE) 232168404Spjd bcopy(dio->io_data, buf + offset, dio->io_size); 233168404Spjd offset += dio->io_size; 234168404Spjd vdev_queue_io_remove(vq, dio); 235168404Spjd zio_vdev_io_bypass(dio); 236168404Spjd nagg++; 237168404Spjd } 238168404Spjd 239168404Spjd ASSERT(offset == size); 240168404Spjd 241168404Spjd dprintf("%5s T=%llu off=%8llx agg=%3d " 242168404Spjd "old=%5llx new=%5llx\n", 243168404Spjd zio_type_name[fio->io_type], 244168404Spjd fio->io_deadline, fio->io_offset, nagg, fio->io_size, size); 245168404Spjd 246168404Spjd avl_add(&vq->vq_pending_tree, aio); 247168404Spjd 248168404Spjd *funcp = zio_nowait; 249168404Spjd return (aio); 250168404Spjd } 251168404Spjd 252168404Spjd ASSERT(fio->io_vdev_tree == tree); 253168404Spjd vdev_queue_io_remove(vq, fio); 254168404Spjd 255168404Spjd avl_add(&vq->vq_pending_tree, fio); 256168404Spjd 257168404Spjd *funcp = zio_next_stage; 258168404Spjd 259168404Spjd return (fio); 260168404Spjd} 261168404Spjd 262168404Spjdzio_t * 263168404Spjdvdev_queue_io(zio_t *zio) 264168404Spjd{ 265168404Spjd vdev_queue_t *vq = &zio->io_vd->vdev_queue; 266168404Spjd zio_t *nio; 267168404Spjd zio_issue_func_t *func; 268168404Spjd 269168404Spjd ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE); 270168404Spjd 271168404Spjd if (zio->io_flags & ZIO_FLAG_DONT_QUEUE) 272168404Spjd return (zio); 273168404Spjd 274168404Spjd zio->io_flags |= ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_QUEUE; 275168404Spjd 276168404Spjd if (zio->io_type == ZIO_TYPE_READ) 277168404Spjd zio->io_vdev_tree = &vq->vq_read_tree; 278168404Spjd else 279168404Spjd zio->io_vdev_tree = &vq->vq_write_tree; 280168404Spjd 281168404Spjd mutex_enter(&vq->vq_lock); 282168404Spjd 283168404Spjd zio->io_deadline = (zio->io_timestamp >> zfs_vdev_time_shift) + 284168404Spjd zio->io_priority; 285168404Spjd 286168404Spjd vdev_queue_io_add(vq, zio); 287168404Spjd 288168404Spjd nio = vdev_queue_io_to_issue(vq, zfs_vdev_min_pending, &func); 289168404Spjd 290168404Spjd mutex_exit(&vq->vq_lock); 291168404Spjd 292168404Spjd if (nio == NULL || func != zio_nowait) 293168404Spjd return (nio); 294168404Spjd 295168404Spjd func(nio); 296168404Spjd return (NULL); 297168404Spjd} 298168404Spjd 299168404Spjdvoid 300168404Spjdvdev_queue_io_done(zio_t *zio) 301168404Spjd{ 302168404Spjd vdev_queue_t *vq = &zio->io_vd->vdev_queue; 303168404Spjd zio_t *nio; 304168404Spjd zio_issue_func_t *func; 305168404Spjd int i; 306168404Spjd 307168404Spjd mutex_enter(&vq->vq_lock); 308168404Spjd 309168404Spjd avl_remove(&vq->vq_pending_tree, zio); 310168404Spjd 311168404Spjd for (i = 0; i < zfs_vdev_ramp_rate; i++) { 312168404Spjd nio = vdev_queue_io_to_issue(vq, zfs_vdev_max_pending, &func); 313168404Spjd if (nio == NULL) 314168404Spjd break; 315168404Spjd mutex_exit(&vq->vq_lock); 316168404Spjd if (func == zio_next_stage) 317168404Spjd zio_vdev_io_reissue(nio); 318168404Spjd func(nio); 319168404Spjd mutex_enter(&vq->vq_lock); 320168404Spjd } 321168404Spjd 322168404Spjd mutex_exit(&vq->vq_lock); 323168404Spjd} 324