diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/Kconfig | 16 | ||||
| -rw-r--r-- | block/Makefile | 1 | ||||
| -rw-r--r-- | block/blk-core.c | 100 | ||||
| -rw-r--r-- | block/blk-merge.c | 29 | ||||
| -rw-r--r-- | block/blk-settings.c | 2 | ||||
| -rw-r--r-- | block/blk-softirq.c | 2 | ||||
| -rw-r--r-- | block/blk-sysfs.c | 44 | ||||
| -rw-r--r-- | block/blk.h | 16 | ||||
| -rw-r--r-- | block/blktrace.c | 860 | ||||
| -rw-r--r-- | block/cfq-iosched.c | 206 | ||||
| -rw-r--r-- | block/elevator.c | 44 |
11 files changed, 244 insertions, 1076 deletions
diff --git a/block/Kconfig b/block/Kconfig index 0cbb3b88b59..e7d12782bcf 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -44,22 +44,6 @@ config LBD If unsure, say N. -config BLK_DEV_IO_TRACE - bool "Support for tracing block io actions" - depends on SYSFS - select RELAY - select DEBUG_FS - select TRACEPOINTS - help - Say Y here if you want to be able to trace the block layer actions - on a given queue. Tracing allows you to see any traffic happening - on a block device queue. For more information (and the userspace - support tools needed), fetch the blktrace tools from: - - git://git.kernel.dk/blktrace.git - - If unsure, say N. - config BLK_DEV_BSG bool "Block layer SG support v4 (EXPERIMENTAL)" depends on EXPERIMENTAL diff --git a/block/Makefile b/block/Makefile index bfe73049f93..e9fa4dd690f 100644 --- a/block/Makefile +++ b/block/Makefile @@ -13,6 +13,5 @@ obj-$(CONFIG_IOSCHED_AS) += as-iosched.o obj-$(CONFIG_IOSCHED_DEADLINE) += deadline-iosched.o obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o -obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o obj-$(CONFIG_BLK_DEV_INTEGRITY) += blk-integrity.o diff --git a/block/blk-core.c b/block/blk-core.c index 996ed906d8c..43fdedc524e 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -64,12 +64,11 @@ static struct workqueue_struct *kblockd_workqueue; static void drive_stat_acct(struct request *rq, int new_io) { - struct gendisk *disk = rq->rq_disk; struct hd_struct *part; int rw = rq_data_dir(rq); int cpu; - if (!blk_fs_request(rq) || !disk || !blk_do_io_stat(disk->queue)) + if (!blk_fs_request(rq) || !blk_do_io_stat(rq)) return; cpu = part_stat_lock(); @@ -484,11 +483,11 @@ static int blk_init_free_list(struct request_queue *q) { struct request_list *rl = &q->rq; - rl->count[READ] = rl->count[WRITE] = 0; - rl->starved[READ] = rl->starved[WRITE] = 0; + rl->count[BLK_RW_SYNC] = rl->count[BLK_RW_ASYNC] = 0; + rl->starved[BLK_RW_SYNC] = rl->starved[BLK_RW_ASYNC] = 0; rl->elvpriv = 0; - init_waitqueue_head(&rl->wait[READ]); - init_waitqueue_head(&rl->wait[WRITE]); + init_waitqueue_head(&rl->wait[BLK_RW_SYNC]); + init_waitqueue_head(&rl->wait[BLK_RW_ASYNC]); rl->rq_pool = mempool_create_node(BLKDEV_MIN_RQ, mempool_alloc_slab, mempool_free_slab, request_cachep, q->node); @@ -699,18 +698,18 @@ static void ioc_set_batching(struct request_queue *q, struct io_context *ioc) ioc->last_waited = jiffies; } -static void __freed_request(struct request_queue *q, int rw) +static void __freed_request(struct request_queue *q, int sync) { struct request_list *rl = &q->rq; - if (rl->count[rw] < queue_congestion_off_threshold(q)) - blk_clear_queue_congested(q, rw); + if (rl->count[sync] < queue_congestion_off_threshold(q)) + blk_clear_queue_congested(q, sync); - if (rl->count[rw] + 1 <= q->nr_requests) { - if (waitqueue_active(&rl->wait[rw])) - wake_up(&rl->wait[rw]); + if (rl->count[sync] + 1 <= q->nr_requests) { + if (waitqueue_active(&rl->wait[sync])) + wake_up(&rl->wait[sync]); - blk_clear_queue_full(q, rw); + blk_clear_queue_full(q, sync); } } @@ -718,18 +717,18 @@ static void __freed_request(struct request_queue *q, int rw) * A request has just been released. Account for it, update the full and * congestion status, wake up any waiters. Called under q->queue_lock. */ -static void freed_request(struct request_queue *q, int rw, int priv) +static void freed_request(struct request_queue *q, int sync, int priv) { struct request_list *rl = &q->rq; - rl->count[rw]--; + rl->count[sync]--; if (priv) rl->elvpriv--; - __freed_request(q, rw); + __freed_request(q, sync); - if (unlikely(rl->starved[rw ^ 1])) - __freed_request(q, rw ^ 1); + if (unlikely(rl->starved[sync ^ 1])) + __freed_request(q, sync ^ 1); } /* @@ -743,15 +742,15 @@ static struct request *get_request(struct request_queue *q, int rw_flags, struct request *rq = NULL; struct request_list *rl = &q->rq; struct io_context *ioc = NULL; - const int rw = rw_flags & 0x01; + const bool is_sync = rw_is_sync(rw_flags) != 0; int may_queue, priv; may_queue = elv_may_queue(q, rw_flags); if (may_queue == ELV_MQUEUE_NO) goto rq_starved; - if (rl->count[rw]+1 >= queue_congestion_on_threshold(q)) { - if (rl->count[rw]+1 >= q->nr_requests) { + if (rl->count[is_sync]+1 >= queue_congestion_on_threshold(q)) { + if (rl->count[is_sync]+1 >= q->nr_requests) { ioc = current_io_context(GFP_ATOMIC, q->node); /* * The queue will fill after this allocation, so set @@ -759,9 +758,9 @@ static struct request *get_request(struct request_queue *q, int rw_flags, * This process will be allowed to complete a batch of * requests, others will be blocked. */ - if (!blk_queue_full(q, rw)) { + if (!blk_queue_full(q, is_sync)) { ioc_set_batching(q, ioc); - blk_set_queue_full(q, rw); + blk_set_queue_full(q, is_sync); } else { if (may_queue != ELV_MQUEUE_MUST && !ioc_batching(q, ioc)) { @@ -774,7 +773,7 @@ static struct request *get_request(struct request_queue *q, int rw_flags, } } } - blk_set_queue_congested(q, rw); + blk_set_queue_congested(q, is_sync); } /* @@ -782,11 +781,11 @@ static struct request *get_request(struct request_queue *q, int rw_flags, * limit of requests, otherwise we could have thousands of requests * allocated with any setting of ->nr_requests */ - if (rl->count[rw] >= (3 * q->nr_requests / 2)) + if (rl->count[is_sync] >= (3 * q->nr_requests / 2)) goto out; - rl->count[rw]++; - rl->starved[rw] = 0; + rl->count[is_sync]++; + rl->starved[is_sync] = 0; priv = !test_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags); if (priv) @@ -804,7 +803,7 @@ static struct request *get_request(struct request_queue *q, int rw_flags, * wait queue, but this is pretty rare. */ spin_lock_irq(q->queue_lock); - freed_request(q, rw, priv); + freed_request(q, is_sync, priv); /* * in the very unlikely event that allocation failed and no @@ -814,8 +813,8 @@ static struct request *get_request(struct request_queue *q, int rw_flags, * rq mempool into READ and WRITE */ rq_starved: - if (unlikely(rl->count[rw] == 0)) - rl->starved[rw] = 1; + if (unlikely(rl->count[is_sync] == 0)) + rl->starved[is_sync] = 1; goto out; } @@ -829,7 +828,7 @@ rq_starved: if (ioc_batching(q, ioc)) ioc->nr_batch_requests--; - trace_block_getrq(q, bio, rw); + trace_block_getrq(q, bio, rw_flags & 1); out: return rq; } @@ -843,7 +842,7 @@ out: static struct request *get_request_wait(struct request_queue *q, int rw_flags, struct bio *bio) { - const int rw = rw_flags & 0x01; + const bool is_sync = rw_is_sync(rw_flags) != 0; struct request *rq; rq = get_request(q, rw_flags, bio, GFP_NOIO); @@ -852,10 +851,10 @@ static struct request *get_request_wait(struct request_queue *q, int rw_flags, struct io_context *ioc; struct request_list *rl = &q->rq; - prepare_to_wait_exclusive(&rl->wait[rw], &wait, + prepare_to_wait_exclusive(&rl->wait[is_sync], &wait, TASK_UNINTERRUPTIBLE); - trace_block_sleeprq(q, bio, rw); + trace_block_sleeprq(q, bio, rw_flags & 1); __generic_unplug_device(q); spin_unlock_irq(q->queue_lock); @@ -871,7 +870,7 @@ static struct request *get_request_wait(struct request_queue *q, int rw_flags, ioc_set_batching(q, ioc); spin_lock_irq(q->queue_lock); - finish_wait(&rl->wait[rw], &wait); + finish_wait(&rl->wait[is_sync], &wait); rq = get_request(q, rw_flags, bio, GFP_NOIO); }; @@ -1070,14 +1069,14 @@ void __blk_put_request(struct request_queue *q, struct request *req) * it didn't come out of our reserved rq pools */ if (req->cmd_flags & REQ_ALLOCED) { - int rw = rq_data_dir(req); + int is_sync = rq_is_sync(req) != 0; int priv = req->cmd_flags & REQ_ELVPRIV; BUG_ON(!list_empty(&req->queuelist)); BUG_ON(!hlist_unhashed(&req->hash)); blk_free_request(q, req); - freed_request(q, rw, priv); + freed_request(q, is_sync, priv); } } EXPORT_SYMBOL_GPL(__blk_put_request); @@ -1124,10 +1123,10 @@ void init_request_from_bio(struct request *req, struct bio *bio) if (bio_sync(bio)) req->cmd_flags |= REQ_RW_SYNC; - if (bio_unplug(bio)) - req->cmd_flags |= REQ_UNPLUG; if (bio_rw_meta(bio)) req->cmd_flags |= REQ_RW_META; + if (bio_noidle(bio)) + req->cmd_flags |= REQ_NOIDLE; req->errors = 0; req->hard_sector = req->sector = bio->bi_sector; @@ -1136,6 +1135,15 @@ void init_request_from_bio(struct request *req, struct bio *bio) blk_rq_bio_prep(req->q, req, bio); } +/* + * Only disabling plugging for non-rotational devices if it does tagging + * as well, otherwise we do need the proper merging + */ +static inline bool queue_should_plug(struct request_queue *q) +{ + return !(blk_queue_nonrot(q) && blk_queue_tagged(q)); +} + static int __make_request(struct request_queue *q, struct bio *bio) { struct request *req; @@ -1242,11 +1250,11 @@ get_rq: if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags) || bio_flagged(bio, BIO_CPU_AFFINE)) req->cpu = blk_cpu_to_group(smp_processor_id()); - if (!blk_queue_nonrot(q) && elv_queue_empty(q)) + if (queue_should_plug(q) && elv_queue_empty(q)) blk_plug_device(q); add_request(q, req); out: - if (unplug || blk_queue_nonrot(q)) + if (unplug || !queue_should_plug(q)) __generic_unplug_device(q); spin_unlock_irq(q->queue_lock); return 0; @@ -1664,9 +1672,7 @@ EXPORT_SYMBOL(blkdev_dequeue_request); static void blk_account_io_completion(struct request *req, unsigned int bytes) { - struct gendisk *disk = req->rq_disk; - - if (!disk || !blk_do_io_stat(disk->queue)) + if (!blk_do_io_stat(req)) return; if (blk_fs_request(req)) { @@ -1683,9 +1689,7 @@ static void blk_account_io_completion(struct request *req, unsigned int bytes) static void blk_account_io_done(struct request *req) { - struct gendisk *disk = req->rq_disk; - - if (!disk || !blk_do_io_stat(disk->queue)) + if (!blk_do_io_stat(req)) return; /* @@ -1700,7 +1704,7 @@ static void blk_account_io_done(struct request *req) int cpu; cpu = part_stat_lock(); - part = disk_map_sector_rcu(disk, req->sector); + part = disk_map_sector_rcu(req->rq_disk, req->sector); part_stat_inc(cpu, part, ios[rw]); part_stat_add(cpu, part, ticks[rw], duration); diff --git a/block/blk-merge.c b/block/blk-merge.c index e39cb24b767..63760ca3da0 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -338,6 +338,22 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req, return 1; } +static void blk_account_io_merge(struct request *req) +{ + if (blk_do_io_stat(req)) { + struct hd_struct *part; + int cpu; + + cpu = part_stat_lock(); + part = disk_map_sector_rcu(req->rq_disk, req->sector); + + part_round_stats(cpu, part); + part_dec_in_flight(part); + + part_stat_unlock(); + } +} + /* * Has to be called with the request spinlock acquired */ @@ -386,18 +402,7 @@ static int attempt_merge(struct request_queue *q, struct request *req, elv_merge_requests(q, req, next); - if (req->rq_disk) { - struct hd_struct *part; - int cpu; - - cpu = part_stat_lock(); - part = disk_map_sector_rcu(req->rq_disk, req->sector); - - part_round_stats(cpu, part); - part_dec_in_flight(part); - - part_stat_unlock(); - } + blk_account_io_merge(req); req->ioprio = ioprio_best(req->ioprio, next->ioprio); if (blk_rq_cpu_valid(next)) diff --git a/block/blk-settings.c b/block/blk-settings.c index 59fd05d9f1d..69c42adde52 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -431,7 +431,7 @@ EXPORT_SYMBOL(blk_queue_segment_boundary); * * description: * set required memory and length alignment for direct dma transactions. - * this is used when buiding direct io requests for the queue. + * this is used when building direct io requests for the queue. * **/ void blk_queue_dma_alignment(struct request_queue *q, int mask) diff --git a/block/blk-softirq.c b/block/blk-softirq.c index ce0efc6b26d..ee9c2160222 100644 --- a/block/blk-softirq.c +++ b/block/blk-softirq.c @@ -64,7 +64,7 @@ static int raise_blk_irq(int cpu, struct request *rq) data->info = rq; data->flags = 0; - __smp_call_function_single(cpu, data); + __smp_call_function_single(cpu, data, 0); return 0; } diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index e29ddfc73cf..73f36beff5c 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -48,28 +48,28 @@ queue_requests_store(struct request_queue *q, const char *page, size_t count) q->nr_requests = nr; blk_queue_congestion_threshold(q); - if (rl->count[READ] >= queue_congestion_on_threshold(q)) - blk_set_queue_congested(q, READ); - else if (rl->count[READ] < queue_congestion_off_threshold(q)) - blk_clear_queue_congested(q, READ); - - if (rl->count[WRITE] >= queue_congestion_on_threshold(q)) - blk_set_queue_congested(q, WRITE); - else if (rl->count[WRITE] < queue_congestion_off_threshold(q)) - blk_clear_queue_congested(q, WRITE); - - if (rl->count[READ] >= q->nr_requests) { - blk_set_queue_full(q, READ); - } else if (rl->count[READ]+1 <= q->nr_requests) { - blk_clear_queue_full(q, READ); - wake_up(&rl->wait[READ]); + if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q)) + blk_set_queue_congested(q, BLK_RW_SYNC); + else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q)) + blk_clear_queue_congested(q, BLK_RW_SYNC); + + if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q)) + blk_set_queue_congested(q, BLK_RW_ASYNC); + else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q)) + blk_clear_queue_congested(q, BLK_RW_ASYNC); + + if (rl->count[BLK_RW_SYNC] >= q->nr_requests) { + blk_set_queue_full(q, BLK_RW_SYNC); + } else if (rl->count[BLK_RW_SYNC]+1 <= q->nr_requests) { + blk_clear_queue_full(q, BLK_RW_SYNC); + wake_up(&rl->wait[BLK_RW_SYNC]); } - if (rl->count[WRITE] >= q->nr_requests) { - blk_set_queue_full(q, WRITE); - } else if (rl->count[WRITE]+1 <= q->nr_requests) { - blk_clear_queue_full(q, WRITE); - wake_up(&rl->wait[WRITE]); + if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) { + blk_set_queue_full(q, BLK_RW_ASYNC); + } else if (rl->count[BLK_RW_ASYNC]+1 <= q->nr_requests) { + blk_clear_queue_full(q, BLK_RW_ASYNC); + wake_up(&rl->wait[BLK_RW_ASYNC]); } spin_unlock_irq(q->queue_lock); return ret; @@ -209,10 +209,14 @@ static ssize_t queue_iostats_store(struct request_queue *q, const char *page, ssize_t ret = queue_var_store(&stats, page, count); spin_lock_irq(q->queue_lock); + elv_quisce_start(q); + if (stats) queue_flag_set(QUEUE_FLAG_IO_STAT, q); else queue_flag_clear(QUEUE_FLAG_IO_STAT, q); + + elv_quisce_end(q); spin_unlock_irq(q->queue_lock); return ret; diff --git a/block/blk.h b/block/blk.h index 0dce92c3749..24fcaeeaf62 100644 --- a/block/blk.h +++ b/block/blk.h @@ -70,6 +70,10 @@ void blk_queue_congestion_threshold(struct request_queue *q); int blk_dev_init(void); +void elv_quisce_start(struct request_queue *q); +void elv_quisce_end(struct request_queue *q); + + /* * Return the threshold (number of used requests) at which the queue is * considered to be congested. It include a little hysteresis to keep the @@ -102,18 +106,20 @@ static inline int blk_cpu_to_group(int cpu) const struct cpumask *mask = cpu_coregroup_mask(cpu); return cpumask_first(mask); #elif defined(CONFIG_SCHED_SMT) - return first_cpu(per_cpu(cpu_sibling_map, cpu)); + return cpumask_first(topology_thread_cpumask(cpu)); #else return cpu; #endif } -static inline int blk_do_io_stat(struct request_queue *q) +static inline int blk_do_io_stat(struct request *rq) { - if (q) - return blk_queue_io_stat(q); + struct gendisk *disk = rq->rq_disk; - return 0; + if (!disk || !disk->queue) + return 0; + + return blk_queue_io_stat(disk->queue) && (rq->cmd_flags & REQ_ELVPRIV); } #endif diff --git a/block/blktrace.c b/block/blktrace.c deleted file mode 100644 index 028120a0965..00000000000 --- a/block/blktrace.c +++ /dev/null @@ -1,860 +0,0 @@ -/* - * Copyright (C) 2006 Jens Axboe <axboe@kernel.dk> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA - * - */ -#include <linux/kernel.h> -#include <linux/blkdev.h> -#include <linux/blktrace_api.h> -#include <linux/percpu.h> -#include <linux/init.h> -#include <linux/mutex.h> -#include <linux/debugfs.h> -#include <linux/time.h> -#include <trace/block.h> -#include <asm/uaccess.h> - -static unsigned int blktrace_seq __read_mostly = 1; - -/* Global reference count of probes */ -static DEFINE_MUTEX(blk_probe_mutex); -static atomic_t blk_probes_ref = ATOMIC_INIT(0); - -static int blk_register_tracepoints(void); -static void blk_unregister_tracepoints(void); - -/* - * Send out a notify message. - */ -static void trace_note(struct blk_trace *bt, pid_t pid, int action, - const void *data, size_t len) -{ - struct blk_io_trace *t; - - t = relay_reserve(bt->rchan, sizeof(*t) + len); - if (t) { - const int cpu = smp_processor_id(); - - t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; - t->time = ktime_to_ns(ktime_get()); - t->device = bt->dev; - t->action = action; - t->pid = pid; - t->cpu = cpu; - t->pdu_len = len; - memcpy((void *) t + sizeof(*t), data, len); - } -} - -/* - * Send out a notify for this process, if we haven't done so since a trace - * started - */ -static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk) -{ - tsk->btrace_seq = blktrace_seq; - trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm, sizeof(tsk->comm)); -} - -static void trace_note_time(struct blk_trace *bt) -{ - struct timespec now; - unsigned long flags; - u32 words[2]; - - getnstimeofday(&now); - words[0] = now.tv_sec; - words[1] = now.tv_nsec; - - local_irq_save(flags); - trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words)); - local_irq_restore(flags); -} - -void __trace_note_message(struct blk_trace *bt, const char *fmt, ...) -{ - int n; - va_list args; - unsigned long flags; - char *buf; - - local_irq_save(flags); - buf = per_cpu_ptr(bt->msg_data, smp_processor_id()); - va_start(args, fmt); - n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args); - va_end(args); - - trace_note(bt, 0, BLK_TN_MESSAGE, buf, n); - local_irq_restore(flags); -} -EXPORT_SYMBOL_GPL(__trace_note_message); - -static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector, - pid_t pid) -{ - if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0) - return 1; - if (sector < bt->start_lba || sector > bt->end_lba) - return 1; - if (bt->pid && pid != bt->pid) - return 1; - - return 0; -} - -/* - * Data direction bit lookup - */ -static u32 ddir_act[2] __read_mostly = { BLK_TC_ACT(BLK_TC_READ), BLK_TC_ACT(BLK_TC_WRITE) }; - -/* The ilog2() calls fall out because they're constant */ -#define MASK_TC_BIT(rw, __name) ( (rw & (1 << BIO_RW_ ## __name)) << \ - (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - BIO_RW_ ## __name) ) - -/* - * The worker for the various blk_add_trace*() types. Fills out a - * blk_io_trace structure and places it in a per-cpu subbuffer. - */ -static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, - int rw, u32 what, int error, int pdu_len, void *pdu_data) -{ - struct task_struct *tsk = current; - struct blk_io_trace *t; - unsigned long flags; - unsigned long *sequence; - pid_t pid; - int cpu; - - if (unlikely(bt->trace_state != Blktrace_running)) - return; - - what |= ddir_act[rw & WRITE]; - what |= MASK_TC_BIT(rw, BARRIER); - what |= MASK_TC_BIT(rw, SYNCIO); - what |= MASK_TC_BIT(rw, AHEAD); - what |= MASK_TC_BIT(rw, META); - what |= MASK_TC_BIT(rw, DISCARD); - - pid = tsk->pid; - if (unlikely(act_log_check(bt, what, sector, pid))) - return; - - /* - * A word about the locking here - we disable interrupts to reserve - * some space in the relay per-cpu buffer, to prevent an irq - * from coming in and stepping on our toes. - */ - local_irq_save(flags); - - if (unlikely(tsk->btrace_seq != blktrace_seq)) - trace_note_tsk(bt, tsk); - - t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len); - if (t) { - cpu = smp_processor_id(); - sequence = per_cpu_ptr(bt->sequence, cpu); - - t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; - t->sequence = ++(*sequence); - t->time = ktime_to_ns(ktime_get()); - t->sector = sector; - t->bytes = bytes; - t->action = what; - t->pid = pid; - t->device = bt->dev; - t->cpu = cpu; - t->error = error; - t->pdu_len = pdu_len; - - if (pdu_len) - memcpy((void *) t + sizeof(*t), pdu_data, pdu_len); - } - - local_irq_restore(flags); -} - -static struct dentry *blk_tree_root; -static DEFINE_MUTEX(blk_tree_mutex); - -static void blk_trace_cleanup(struct blk_trace *bt) -{ - debugfs_remove(bt->msg_file); - debugfs_remove(bt->dropped_file); - relay_close(bt->rchan); - free_percpu(bt->sequence); - free_percpu(bt->msg_data); - kfree(bt); - mutex_lock(&blk_probe_mutex); - if (atomic_dec_and_test(&blk_probes_ref)) - blk_unregister_tracepoints(); - mutex_unlock(&blk_probe_mutex); -} - -int blk_trace_remove(struct request_queue *q) -{ - struct blk_trace *bt; - - bt = xchg(&q->blk_trace, NULL); - if (!bt) - return -EINVAL; - - if (bt->trace_state == Blktrace_setup || - bt->trace_state == Blktrace_stopped) - blk_trace_cleanup(bt); - - return 0; -} -EXPORT_SYMBOL_GPL(blk_trace_remove); - -static int blk_dropped_open(struct inode *inode, struct file *filp) -{ - filp->private_data = inode->i_private; - - return 0; -} - -static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, - size_t count, loff_t *ppos) -{ - struct blk_trace *bt = filp->private_data; - char buf[16]; - - snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped)); - - return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf)); -} - -static const struct file_operations blk_dropped_fops = { - .owner = THIS_MODULE, - .open = blk_dropped_open, - .read = blk_dropped_read, -}; - -static int blk_msg_open(struct inode *inode, struct file *filp) -{ - filp->private_data = inode->i_private; - - return 0; -} - -static ssize_t blk_msg_write(struct file *filp, const char __user *buffer, - size_t count, loff_t *ppos) -{ - char *msg; - struct blk_trace *bt; - - if (count > BLK_TN_MAX_MSG) - return -EINVAL; - - msg = kmalloc(count, GFP_KERNEL); - if (msg == NULL) - return -ENOMEM; - - if (copy_from_user(msg, buffer, count)) { - kfree(msg); - return -EFAULT; - } - - bt = filp->private_data; - __trace_note_message(bt, "%s", msg); - kfree(msg); - - return count; -} - -static const struct file_operations blk_msg_fops = { - .owner = THIS_MODULE, - .open = blk_msg_open, - .write = blk_msg_write, -}; - -/* - * Keep track of how many times we encountered a full subbuffer, to aid - * the user space app in telling how many lost events there were. - */ -static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf, - void *prev_subbuf, size_t prev_padding) -{ - struct blk_trace *bt; - - if (!relay_buf_full(buf)) - return 1; - - bt = buf->chan->private_data; - atomic_inc(&bt->dropped); - return 0; -} - -static int blk_remove_buf_file_callback(struct dentry *dentry) -{ - struct dentry *parent = dentry->d_parent; - debugfs_remove(dentry); - - /* - * this will fail for all but the last file, but that is ok. what we - * care about is the top level buts->name directory going away, when - * the last trace file is gone. Then we don't have to rmdir() that - * manually on trace stop, so it nicely solves the issue with - * force killing of running traces. - */ - - debugfs_remove(parent); - return 0; -} - -static struct dentry *blk_create_buf_file_callback(const char *filename, - struct dentry *parent, - int mode, - struct rchan_buf *buf, - int *is_global) -{ - return debugfs_create_file(filename, mode, parent, buf, - &relay_file_operations); -} - -static struct rchan_callbacks blk_relay_callbacks = { - .subbuf_start = blk_subbuf_start_callback, - .create_buf_file = blk_create_buf_file_callback, - .remove_buf_file = blk_remove_buf_file_callback, -}; - -/* - * Setup everything required to start tracing - */ -int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, - struct blk_user_trace_setup *buts) -{ - struct blk_trace *old_bt, *bt = NULL; - struct dentry *dir = NULL; - int ret, i; - - if (!buts->buf_size || !buts->buf_nr) - return -EINVAL; - - strncpy(buts->name, name, BLKTRACE_BDEV_SIZE); - buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0'; - - /* - * some device names have larger paths - convert the slashes - * to underscores for this to work as expected - */ - for (i = 0; i < strlen(buts->name); i++) - if (buts->name[i] == '/') - buts->name[i] = '_'; - - ret = -ENOMEM; - bt = kzalloc(sizeof(*bt), GFP_KERNEL); - if (!bt) - goto err; - - bt->sequence = alloc_percpu(unsigned long); - if (!bt->sequence) - goto err; - - bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char)); - if (!bt->msg_data) - goto err; - - ret = -ENOENT; - - if (!blk_tree_root) { - blk_tree_root = debugfs_create_dir("block", NULL); - if (!blk_tree_root) - return -ENOMEM; - } - - dir = debugfs_create_dir(buts->name, blk_tree_root); - - if (!dir) - goto err; - - bt->dir = dir; - bt->dev = dev; - atomic_set(&bt->dropped, 0); - - ret = -EIO; - bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, &blk_dropped_fops); - if (!bt->dropped_file) - goto err; - - bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops); - if (!bt->msg_file) - goto err; - - bt->rchan = relay_open("trace", dir, buts->buf_size, - buts->buf_nr, &blk_relay_callbacks, bt); - if (!bt->rchan) - goto err; - - bt->act_mask = buts->act_mask; - if (!bt->act_mask) - bt->act_mask = (u16) -1; - - bt->start_lba = buts->start_lba; - bt->end_lba = buts->end_lba; - if (!bt->end_lba) - bt->end_lba = -1ULL; - - bt->pid = buts->pid; - bt->trace_state = Blktrace_setup; - - mutex_lock(&blk_probe_mutex); - if (atomic_add_return(1, &blk_probes_ref) == 1) { - ret = blk_register_tracepoints(); - if (ret) - goto probe_err; - } - mutex_unlock(&blk_probe_mutex); - - ret = -EBUSY; - old_bt = xchg(&q->blk_trace, bt); - if (old_bt) { - (void) xchg(&q->blk_trace, old_bt); - goto err; - } - - return 0; -probe_err: - atomic_dec(&blk_probes_ref); - mutex_unlock(&blk_probe_mutex); -err: - if (bt) { - if (bt->msg_file) - debugfs_remove(bt->msg_file); - if (bt->dropped_file) - debugfs_remove(bt->dropped_file); - free_percpu(bt->sequence); - free_percpu(bt->msg_data); - if (bt->rchan) - relay_close(bt->rchan); - kfree(bt); - } - return ret; -} - -int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, - char __user *arg) -{ - struct blk_user_trace_setup buts; - int ret; - - ret = copy_from_user(&buts, arg, sizeof(buts)); - if (ret) - return -EFAULT; - - ret = do_blk_trace_setup(q, name, dev, &buts); - if (ret) - return ret; - - if (copy_to_user(arg, &buts, sizeof(buts))) - return -EFAULT; - - return 0; -} -EXPORT_SYMBOL_GPL(blk_trace_setup); - -int blk_trace_startstop(struct request_queue *q, int start) -{ - struct blk_trace *bt; - int ret; - - if ((bt = q->blk_trace) == NULL) - return -EINVAL; - - /* - * For starting a trace, we can transition from a setup or stopped - * trace. For stopping a trace, the state must be running - */ - ret = -EINVAL; - if (start) { - if (bt->trace_state == Blktrace_setup || - bt->trace_state == Blktrace_stopped) { - blktrace_seq++; - smp_mb(); - bt->trace_state = Blktrace_running; - - trace_note_time(bt); - ret = 0; - } - } else { - if (bt->trace_state == Blktrace_running) { - bt->trace_state = Blktrace_stopped; - relay_flush(bt->rchan); - ret = 0; - } - } - - return ret; -} -EXPORT_SYMBOL_GPL(blk_trace_startstop); - -/** - * blk_trace_ioctl: - handle the ioctls associated with tracing - * @bdev: the block device - * @cmd: the ioctl cmd - * @arg: the argument data, if any - * - **/ -int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) -{ - struct request_queue *q; - int ret, start = 0; - char b[BDEVNAME_SIZE]; - - q = bdev_get_queue(bdev); - if (!q) - return -ENXIO; - - mutex_lock(&bdev->bd_mutex); - - switch (cmd) { - case BLKTRACESETUP: - bdevname(bdev, b); - ret = blk_trace_setup(q, b, bdev->bd_dev, arg); - break; - case BLKTRACESTART: - start = 1; - case BLKTRACESTOP: - ret = blk_trace_startstop(q, start); - break; - case BLKTRACETEARDOWN: - ret = blk_trace_remove(q); - break; - default: - ret = -ENOTTY; - break; - } - - mutex_unlock(&bdev->bd_mutex); - return ret; -} - -/** - * blk_trace_shutdown: - stop and cleanup trace structures - * @q: the request queue associated with the device - * - **/ -void blk_trace_shutdown(struct request_queue *q) -{ - if (q->blk_trace) { - blk_trace_startstop(q, 0); - blk_trace_remove(q); - } -} - -/* - * blktrace probes - */ - -/** - * blk_add_trace_rq - Add a trace for a request oriented action - * @q: queue the io is for - * @rq: the source request - * @what: the action - * - * Description: - * Records an action against a request. Will log the bio offset + size. - * - **/ -static void blk_add_trace_rq(struct request_queue *q, struct request *rq, - u32 what) -{ - struct blk_trace *bt = q->blk_trace; - int rw = rq->cmd_flags & 0x03; - - if (likely(!bt)) - return; - - if (blk_discard_rq(rq)) - rw |= (1 << BIO_RW_DISCARD); - - if (blk_pc_request(rq)) { - what |= BLK_TC_ACT(BLK_TC_PC); - __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, - sizeof(rq->cmd), rq->cmd); - } else { - what |= BLK_TC_ACT(BLK_TC_FS); - __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, - rw, what, rq->errors, 0, NULL); - } -} - -static void blk_add_trace_rq_abort(struct request_queue *q, struct request *rq) -{ - blk_add_trace_rq(q, rq, BLK_TA_ABORT); -} - -static void blk_add_trace_rq_insert(struct request_queue *q, struct request *rq) -{ - blk_add_trace_rq(q, rq, BLK_TA_INSERT); -} - -static void blk_add_trace_rq_issue(struct request_queue *q, struct request *rq) -{ - blk_add_trace_rq(q, rq, BLK_TA_ISSUE); -} - -static void blk_add_trace_rq_requeue(struct request_queue *q, struct request *rq) -{ - blk_add_trace_rq(q, rq, BLK_TA_REQUEUE); -} - -static void blk_add_trace_rq_complete(struct request_queue *q, struct request *rq) -{ - blk_add_trace_rq(q, rq, BLK_TA_COMPLETE); -} - -/** - * blk_add_trace_bio - Add a trace for a bio oriented action - * @q: queue the io is for - * @bio: the source bio - * @what: the action - * - * Description: - * Records an action against a bio. Will log the bio offset + size. - * - **/ -static void blk_add_trace_bio(struct request_queue *q, struct bio *bio, - u32 what) -{ - struct blk_trace *bt = q->blk_trace; - - if (likely(!bt)) - return; - - __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, - !bio_flagged(bio, BIO_UPTODATE), 0, NULL); -} - -static void blk_add_trace_bio_bounce(struct request_queue *q, struct bio *bio) -{ - blk_add_trace_bio(q, bio, BLK_TA_BOUNCE); -} - -static void blk_add_trace_bio_complete(struct request_queue *q, struct bio *bio) -{ - blk_add_trace_bio(q, bio, BLK_TA_COMPLETE); -} - -static void blk_add_trace_bio_backmerge(struct request_queue *q, struct bio *bio) -{ - blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE); -} - -static void blk_add_trace_bio_frontmerge(struct request_queue *q, struct bio *bio) -{ - blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE); -} - -static void blk_add_trace_bio_queue(struct request_queue *q, struct bio *bio) -{ - blk_add_trace_bio(q, bio, BLK_TA_QUEUE); -} - -static void blk_add_trace_getrq(struct request_queue *q, struct bio *bio, int rw) -{ - if (bio) - blk_add_trace_bio(q, bio, BLK_TA_GETRQ); - else { - struct blk_trace *bt = q->blk_trace; - - if (bt) - __blk_add_trace(bt, 0, 0, rw, BLK_TA_GETRQ, 0, 0, NULL); - } -} - - -static void blk_add_trace_sleeprq(struct request_queue *q, struct bio *bio, int rw) -{ - if (bio) - blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ); - else { - struct blk_trace *bt = q->blk_trace; - - if (bt) - __blk_add_trace(bt, 0, 0, rw, BLK_TA_SLEEPRQ, 0, 0, NULL); - } -} - -static void blk_add_trace_plug(struct request_queue *q) -{ - struct blk_trace *bt = q->blk_trace; - - if (bt) - __blk_add_trace(bt, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL); -} - -static void blk_add_trace_unplug_io(struct request_queue *q) -{ - struct blk_trace *bt = q->blk_trace; - - if (bt) { - unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE]; - __be64 rpdu = cpu_to_be64(pdu); - - __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_IO, 0, - sizeof(rpdu), &rpdu); - } -} - -static void blk_add_trace_unplug_timer(struct request_queue *q) -{ - struct blk_trace *bt = q->blk_trace; - - if (bt) { - unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE]; - __be64 rpdu = cpu_to_be64(pdu); - - __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_TIMER, 0, - sizeof(rpdu), &rpdu); - } -} - -static void blk_add_trace_split(struct request_queue *q, struct bio *bio, - unsigned int pdu) -{ - struct blk_trace *bt = q->blk_trace; - - if (bt) { - __be64 rpdu = cpu_to_be64(pdu); - - __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, - BLK_TA_SPLIT, !bio_flagged(bio, BIO_UPTODATE), - sizeof(rpdu), &rpdu); - } -} - -/** - * blk_add_trace_remap - Add a trace for a remap operation - * @q: queue the io is for - * @bio: the source bio - * @dev: target device - * @from: source sector - * @to: target sector - * - * Description: - * Device mapper or raid target sometimes need to split a bio because - * it spans a stripe (or similar). Add a trace for that action. - * - **/ -static void blk_add_trace_remap(struct request_queue *q, struct bio *bio, - dev_t dev, sector_t from, sector_t to) -{ - struct blk_trace *bt = q->blk_trace; - struct blk_io_trace_remap r; - - if (likely(!bt)) - return; - - r.device = cpu_to_be32(dev); - r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev); - r.sector = cpu_to_be64(to); - - __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, - !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r); -} - -/** - * blk_add_driver_data - Add binary message with driver-specific data - * @q: queue the io is for - * @rq: io request - * @data: driver-specific data - * @len: length of driver-specific data - * - * Description: - * Some drivers might want to write driver-specific data per request. - * - **/ -void blk_add_driver_data(struct request_queue *q, - struct request *rq, - void *data, size_t len) -{ - struct blk_trace *bt = q->blk_trace; - - if (likely(!bt)) - return; - - if (blk_pc_request(rq)) - __blk_add_trace(bt, 0, rq->data_len, 0, BLK_TA_DRV_DATA, - rq->errors, len, data); - else - __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, - 0, BLK_TA_DRV_DATA, rq->errors, len, data); -} -EXPORT_SYMBOL_GPL(blk_add_driver_data); - -static int blk_register_tracepoints(void) -{ - int ret; - - ret = register_trace_block_rq_abort(blk_add_trace_rq_abort); - WARN_ON(ret); - ret = register_trace_block_rq_insert(blk_add_trace_rq_insert); - WARN_ON(ret); - ret = register_trace_block_rq_issue(blk_add_trace_rq_issue); - WARN_ON(ret); - ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue); - WARN_ON(ret); - ret = register_trace_block_rq_complete(blk_add_trace_rq_complete); - WARN_ON(ret); - ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce); - WARN_ON(ret); - ret = register_trace_block_bio_complete(blk_add_trace_bio_complete); - WARN_ON(ret); - ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge); - WARN_ON(ret); - ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge); - WARN_ON(ret); - ret = register_trace_block_bio_queue(blk_add_trace_bio_queue); - WARN_ON(ret); - ret = register_trace_block_getrq(blk_add_trace_getrq); - WARN_ON(ret); - ret = register_trace_block_sleeprq(blk_add_trace_sleeprq); - WARN_ON(ret); - ret = register_trace_block_plug(blk_add_trace_plug); - WARN_ON(ret); - ret = register_trace_block_unplug_timer(blk_add_trace_unplug_timer); - WARN_ON(ret); - ret = register_trace_block_unplug_io(blk_add_trace_unplug_io); - WARN_ON(ret); - ret = register_trace_block_split(blk_add_trace_split); - WARN_ON(ret); - ret = register_trace_block_remap(blk_add_trace_remap); - WARN_ON(ret); - return 0; -} - -static void blk_unregister_tracepoints(void) -{ - unregister_trace_block_remap(blk_add_trace_remap); - unregister_trace_block_split(blk_add_trace_split); - unregister_trace_block_unplug_io(blk_add_trace_unplug_io); - unregister_trace_block_unplug_timer(blk_add_trace_unplug_timer); - unregister_trace_block_plug(blk_add_trace_plug); - unregister_trace_block_sleeprq(blk_add_trace_sleeprq); - unregister_trace_block_getrq(blk_add_trace_getrq); - unregister_trace_block_bio_queue(blk_add_trace_bio_queue); - unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge); - unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge); - unregister_trace_block_bio_complete(blk_add_trace_bio_complete); - unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce); - unregister_trace_block_rq_complete(blk_add_trace_rq_complete); - unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue); - unregister_trace_block_rq_issue(blk_add_trace_rq_issue); - unregister_trace_block_rq_insert(blk_add_trace_rq_insert); - unregister_trace_block_rq_abort(blk_add_trace_rq_abort); - - tracepoint_synchronize_unregister(); -} diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 664ebfd092e..a4809de6fea 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -160,6 +160,7 @@ struct cfq_queue { unsigned long slice_end; long slice_resid; + unsigned int slice_dispatch; /* pending metadata requests */ int meta_pending; @@ -176,13 +177,12 @@ struct cfq_queue { enum cfqq_state_flags { CFQ_CFQQ_FLAG_on_rr = 0, /* on round-robin busy list */ CFQ_CFQQ_FLAG_wait_request, /* waiting for a request */ + CFQ_CFQQ_FLAG_must_dispatch, /* must be allowed a dispatch */ CFQ_CFQQ_FLAG_must_alloc, /* must be allowed rq alloc */ CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */ - CFQ_CFQQ_FLAG_must_dispatch, /* must dispatch, even if expired */ CFQ_CFQQ_FLAG_fifo_expire, /* FIFO checked in this slice */ CFQ_CFQQ_FLAG_idle_window, /* slice idling enabled */ CFQ_CFQQ_FLAG_prio_changed, /* task priority has changed */ - CFQ_CFQQ_FLAG_queue_new, /* queue never been serviced */ CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */ CFQ_CFQQ_FLAG_sync, /* synchronous queue */ }; @@ -203,13 +203,12 @@ static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \ CFQ_CFQQ_FNS(on_rr); CFQ_CFQQ_FNS(wait_request); +CFQ_CFQQ_FNS(must_dispatch); CFQ_CFQQ_FNS(must_alloc); CFQ_CFQQ_FNS(must_alloc_slice); -CFQ_CFQQ_FNS(must_dispatch); CFQ_CFQQ_FNS(fifo_expire); CFQ_CFQQ_FNS(idle_window); CFQ_CFQQ_FNS(prio_changed); -CFQ_CFQQ_FNS(queue_new); CFQ_CFQQ_FNS(slice_new); CFQ_CFQQ_FNS(sync); #undef CFQ_CFQQ_FNS @@ -774,10 +773,15 @@ static void __cfq_set_active_queue(struct cfq_data *cfqd, if (cfqq) { cfq_log_cfqq(cfqd, cfqq, "set_active"); cfqq->slice_end = 0; + cfqq->slice_dispatch = 0; + + cfq_clear_cfqq_wait_request(cfqq); + cfq_clear_cfqq_must_dispatch(cfqq); cfq_clear_cfqq_must_alloc_slice(cfqq); cfq_clear_cfqq_fifo_expire(cfqq); cfq_mark_cfqq_slice_new(cfqq); - cfq_clear_cfqq_queue_new(cfqq); + + del_timer(&cfqd->idle_slice_timer); } cfqd->active_queue = cfqq; @@ -795,7 +799,6 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, if (cfq_cfqq_wait_request(cfqq)) del_timer(&cfqd->idle_slice_timer); - cfq_clear_cfqq_must_dispatch(cfqq); cfq_clear_cfqq_wait_request(cfqq); /* @@ -924,7 +927,6 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd) (sample_valid(cic->ttime_samples) && cic->ttime_mean > 2)) return; - cfq_mark_cfqq_must_dispatch(cfqq); cfq_mark_cfqq_wait_request(cfqq); /* @@ -1010,7 +1012,7 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) /* * The active queue has run out of time, expire it and select new. */ - if (cfq_slice_used(cfqq)) + if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) goto expire; /* @@ -1053,66 +1055,6 @@ keep_queue: return cfqq; } -/* - * Dispatch some requests from cfqq, moving them to the request queue - * dispatch list. - */ -static int -__cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq, - int max_dispatch) -{ - int dispatched = 0; - - BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); - - do { - struct request *rq; - - /* - * follow expired path, else get first next available - */ - rq = cfq_check_fifo(cfqq); - if (rq == NULL) - rq = cfqq->next_rq; - - /* - * finally, insert request into driver dispatch list - */ - cfq_dispatch_insert(cfqd->queue, rq); - - dispatched++; - - if (!cfqd->active_cic) { - atomic_inc(&RQ_CIC(rq)->ioc->refcount); - cfqd->active_cic = RQ_CIC(rq); - } - - if (RB_EMPTY_ROOT(&cfqq->sort_list)) - break; - - /* - * If there is a non-empty RT cfqq waiting for current - * cfqq's timeslice to complete, pre-empt this cfqq - */ - if (!cfq_class_rt(cfqq) && cfqd->busy_rt_queues) - break; - - } while (dispatched < max_dispatch); - - /* - * expire an async queue immediately if it has used up its slice. idle - * queue always expire after 1 dispatch round. - */ - if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && - dispatched >= cfq_prio_to_maxrq(cfqd, cfqq)) || - cfq_class_idle(cfqq))) { - cfqq->slice_end = jiffies + 1; - cfq_slice_expired(cfqd, 0); - } - - return dispatched; -} - static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) { int dispatched = 0; @@ -1146,11 +1088,45 @@ static int cfq_forced_dispatch(struct cfq_data *cfqd) return dispatched; } +/* + * Dispatch a request from cfqq, moving them to the request queue + * dispatch list. + */ +static void cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq) +{ + struct request *rq; + + BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); + + /* + * follow expired path, else get first next available + */ + rq = cfq_check_fifo(cfqq); + if (!rq) + rq = cfqq->next_rq; + + /* + * insert request into driver dispatch list + */ + cfq_dispatch_insert(cfqd->queue, rq); + + if (!cfqd->active_cic) { + struct cfq_io_context *cic = RQ_CIC(rq); + + atomic_inc(&cic->ioc->refcount); + cfqd->active_cic = cic; + } +} + +/* + * Find the cfqq that we need to service and move a request from that to the + * dispatch list + */ static int cfq_dispatch_requests(struct request_queue *q, int force) { struct cfq_data *cfqd = q->elevator->elevator_data; struct cfq_queue *cfqq; - int dispatched; + unsigned int max_dispatch; if (!cfqd->busy_queues) return 0; @@ -1158,29 +1134,63 @@ static int cfq_dispatch_requests(struct request_queue *q, int force) if (unlikely(force)) return cfq_forced_dispatch(cfqd); - dispatched = 0; - while ((cfqq = cfq_select_queue(cfqd)) != NULL) { - int max_dispatch; + cfqq = cfq_select_queue(cfqd); + if (!cfqq) + return 0; + + /* + * If this is an async queue and we have sync IO in flight, let it wait + */ + if (cfqd->sync_flight && !cfq_cfqq_sync(cfqq)) + return 0; + + max_dispatch = cfqd->cfq_quantum; + if (cfq_class_idle(cfqq)) + max_dispatch = 1; - max_dispatch = cfqd->cfq_quantum; + /* + * Does this cfqq already have too much IO in flight? + */ + if (cfqq->dispatched >= max_dispatch) { + /* + * idle queue must always only have a single IO in flight + */ if (cfq_class_idle(cfqq)) - max_dispatch = 1; + return 0; - if (cfqq->dispatched >= max_dispatch && cfqd->busy_queues > 1) - break; + /* + * We have other queues, don't allow more IO from this one + */ + if (cfqd->busy_queues > 1) + return 0; - if (cfqd->sync_flight && !cfq_cfqq_sync(cfqq)) - break; + /* + * we are the only queue, allow up to 4 times of 'quantum' + */ + if (cfqq->dispatched >= 4 * max_dispatch) + return 0; + } - cfq_clear_cfqq_must_dispatch(cfqq); - cfq_clear_cfqq_wait_request(cfqq); - del_timer(&cfqd->idle_slice_timer); + /* + * Dispatch a request from this cfqq + */ + cfq_dispatch_request(cfqd, cfqq); + cfqq->slice_dispatch++; + cfq_clear_cfqq_must_dispatch(cfqq); - dispatched += __cfq_dispatch_requests(cfqd, cfqq, max_dispatch); + /* + * expire an async queue immediately if it has used up its slice. idle + * queue always expire after 1 dispatch round. + */ + if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && + cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) || + cfq_class_idle(cfqq))) { + cfqq->slice_end = jiffies + 1; + cfq_slice_expired(cfqd, 0); } - cfq_log(cfqd, "dispatched=%d", dispatched); - return dispatched; + cfq_log(cfqd, "dispatched a request"); + return 1; } /* @@ -1506,7 +1516,6 @@ retry: cfqq->cfqd = cfqd; cfq_mark_cfqq_prio_changed(cfqq); - cfq_mark_cfqq_queue_new(cfqq); cfq_init_prio_data(cfqq, ioc); @@ -1893,15 +1902,13 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, if (cfqq == cfqd->active_queue) { /* - * if we are waiting for a request for this queue, let it rip - * immediately and flag that we must not expire this queue - * just now + * Remember that we saw a request from this process, but + * don't start queuing just yet. Otherwise we risk seeing lots + * of tiny requests, because we disrupt the normal plugging + * and merging. */ - if (cfq_cfqq_wait_request(cfqq)) { + if (cfq_cfqq_wait_request(cfqq)) cfq_mark_cfqq_must_dispatch(cfqq); - del_timer(&cfqd->idle_slice_timer); - blk_start_queueing(cfqd->queue); - } } else if (cfq_should_preempt(cfqd, cfqq, rq)) { /* * not the active queue - expire current slice if it is @@ -1910,7 +1917,6 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, * this new queue is RT and the current one is BE */ cfq_preempt_queue(cfqd, cfqq); - cfq_mark_cfqq_must_dispatch(cfqq); blk_start_queueing(cfqd->queue); } } @@ -1992,8 +1998,10 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq) } if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq)) cfq_slice_expired(cfqd, 1); - else if (sync && RB_EMPTY_ROOT(&cfqq->sort_list)) + else if (sync && !rq_noidle(rq) && + RB_EMPTY_ROOT(&cfqq->sort_list)) { cfq_arm_slice_timer(cfqd); + } } if (!cfqd->rq_in_driver) @@ -2170,6 +2178,12 @@ static void cfq_idle_slice_timer(unsigned long data) timed_out = 0; /* + * We saw a request before the queue expired, let it through + */ + if (cfq_cfqq_must_dispatch(cfqq)) + goto out_kick; + + /* * expired */ if (cfq_slice_used(cfqq)) @@ -2185,10 +2199,8 @@ static void cfq_idle_slice_timer(unsigned long data) /* * not expired and it has a request pending, let it dispatch */ - if (!RB_EMPTY_ROOT(&cfqq->sort_list)) { - cfq_mark_cfqq_must_dispatch(cfqq); + if (!RB_EMPTY_ROOT(&cfqq->sort_list)) goto out_kick; - } } expire: cfq_slice_expired(cfqd, timed_out); diff --git a/block/elevator.c b/block/elevator.c index 98259eda0ef..fb81bcc14a8 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -573,7 +573,7 @@ void elv_requeue_request(struct request_queue *q, struct request *rq) elv_insert(q, rq, ELEVATOR_INSERT_REQUEUE); } -static void elv_drain_elevator(struct request_queue *q) +void elv_drain_elevator(struct request_queue *q) { static int printed; while (q->elevator->ops->elevator_dispatch_fn(q, 1)) @@ -587,6 +587,31 @@ static void elv_drain_elevator(struct request_queue *q) } } +/* + * Call with queue lock held, interrupts disabled + */ +void elv_quisce_start(struct request_queue *q) +{ + queue_flag_set(QUEUE_FLAG_ELVSWITCH, q); + + /* + * make sure we don't have any requests in flight + */ + elv_drain_elevator(q); + while (q->rq.elvpriv) { + blk_start_queueing(q); + spin_unlock_irq(q->queue_lock); + msleep(10); + spin_lock_irq(q->queue_lock); + elv_drain_elevator(q); + } +} + +void elv_quisce_end(struct request_queue *q) +{ + queue_flag_clear(QUEUE_FLAG_ELVSWITCH, q); +} + void elv_insert(struct request_queue *q, struct request *rq, int where) { struct list_head *pos; @@ -677,7 +702,7 @@ void elv_insert(struct request_queue *q, struct request *rq, int where) } if (unplug_it && blk_queue_plugged(q)) { - int nrq = q->rq.count[READ] + q->rq.count[WRITE] + int nrq = q->rq.count[BLK_RW_SYNC] + q->rq.count[BLK_RW_ASYNC] - q->in_flight; if (nrq >= q->unplug_thresh) @@ -1101,18 +1126,7 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e) * Turn on BYPASS and drain all requests w/ elevator private data */ spin_lock_irq(q->queue_lock); - - queue_flag_set(QUEUE_FLAG_ELVSWITCH, q); - - elv_drain_elevator(q); - - while (q->rq.elvpriv) { - blk_start_queueing(q); - spin_unlock_irq(q->queue_lock); - msleep(10); - spin_lock_irq(q->queue_lock); - elv_drain_elevator(q); - } + elv_quisce_start(q); /* * Remember old elevator. @@ -1136,7 +1150,7 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e) */ elevator_exit(old_elevator); spin_lock_irq(q->queue_lock); - queue_flag_clear(QUEUE_FLAG_ELVSWITCH, q); + elv_quisce_end(q); spin_unlock_irq(q->queue_lock); blk_add_trace_msg(q, "elv switch: %s", e->elevator_type->elevator_name); |