aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/md/dm.c
diff options
context:
space:
mode:
authorNikanth Karthikesan <knikanth@suse.de>2009-09-11 03:18:54 -0400
committerJens Axboe <jens.axboe@oracle.com>2009-09-14 02:24:52 -0400
commita9327cac440be4d8333bba975cbbf76045096275 (patch)
tree83fd5dc45dc925c5b4eb0264c3add96cfaa4cae6 /drivers/md/dm.c
parent18d8217bc441630c3c5ec7416c5a65c69e8a0979 (diff)
Seperate read and write statistics of in_flight requests
Currently, there is a single in_flight counter measuring the number of requests in the request_queue. But some monitoring tools would like to know how many read requests and write requests are in progress. Split the current in_flight counter into two seperate counters for read and write. This information is exported as a sysfs attribute, as changing the currently available stat files would break the existing tools. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'drivers/md/dm.c')
-rw-r--r--drivers/md/dm.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index ec012f030240..eee28fac210c 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -130,7 +130,7 @@ struct mapped_device {
130 /* 130 /*
131 * A list of ios that arrived while we were suspended. 131 * A list of ios that arrived while we were suspended.
132 */ 132 */
133 atomic_t pending; 133 atomic_t pending[2];
134 wait_queue_head_t wait; 134 wait_queue_head_t wait;
135 struct work_struct work; 135 struct work_struct work;
136 struct bio_list deferred; 136 struct bio_list deferred;
@@ -453,13 +453,14 @@ static void start_io_acct(struct dm_io *io)
453{ 453{
454 struct mapped_device *md = io->md; 454 struct mapped_device *md = io->md;
455 int cpu; 455 int cpu;
456 int rw = bio_data_dir(io->bio);
456 457
457 io->start_time = jiffies; 458 io->start_time = jiffies;
458 459
459 cpu = part_stat_lock(); 460 cpu = part_stat_lock();
460 part_round_stats(cpu, &dm_disk(md)->part0); 461 part_round_stats(cpu, &dm_disk(md)->part0);
461 part_stat_unlock(); 462 part_stat_unlock();
462 dm_disk(md)->part0.in_flight = atomic_inc_return(&md->pending); 463 dm_disk(md)->part0.in_flight[rw] = atomic_inc_return(&md->pending[rw]);
463} 464}
464 465
465static void end_io_acct(struct dm_io *io) 466static void end_io_acct(struct dm_io *io)
@@ -479,8 +480,9 @@ static void end_io_acct(struct dm_io *io)
479 * After this is decremented the bio must not be touched if it is 480 * After this is decremented the bio must not be touched if it is
480 * a barrier. 481 * a barrier.
481 */ 482 */
482 dm_disk(md)->part0.in_flight = pending = 483 dm_disk(md)->part0.in_flight[rw] = pending =
483 atomic_dec_return(&md->pending); 484 atomic_dec_return(&md->pending[rw]);
485 pending += atomic_read(&md->pending[rw^0x1]);
484 486
485 /* nudge anyone waiting on suspend queue */ 487 /* nudge anyone waiting on suspend queue */
486 if (!pending) 488 if (!pending)
@@ -1785,7 +1787,8 @@ static struct mapped_device *alloc_dev(int minor)
1785 if (!md->disk) 1787 if (!md->disk)
1786 goto bad_disk; 1788 goto bad_disk;
1787 1789
1788 atomic_set(&md->pending, 0); 1790 atomic_set(&md->pending[0], 0);
1791 atomic_set(&md->pending[1], 0);
1789 init_waitqueue_head(&md->wait); 1792 init_waitqueue_head(&md->wait);
1790 INIT_WORK(&md->work, dm_wq_work); 1793 INIT_WORK(&md->work, dm_wq_work);
1791 init_waitqueue_head(&md->eventq); 1794 init_waitqueue_head(&md->eventq);
@@ -2088,7 +2091,8 @@ static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
2088 break; 2091 break;
2089 } 2092 }
2090 spin_unlock_irqrestore(q->queue_lock, flags); 2093 spin_unlock_irqrestore(q->queue_lock, flags);
2091 } else if (!atomic_read(&md->pending)) 2094 } else if (!atomic_read(&md->pending[0]) &&
2095 !atomic_read(&md->pending[1]))
2092 break; 2096 break;
2093 2097
2094 if (interruptible == TASK_INTERRUPTIBLE && 2098 if (interruptible == TASK_INTERRUPTIBLE &&