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dm: consolidate spinlocks in dm_io struct

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No reason to have separate startio_lock and endio_lock given endio_lock
could be used during submission anyway.

This change leaves the dm_io struct weighing in at 256 bytes (down
from 272 bytes, so saves a cacheline).

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
This commit is contained in:
Mike Snitzer 2022-03-19 18:41:16 -04:00
parent bd4a6dd241
commit 4d7bca13dd
2 changed files with 6 additions and 8 deletions
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3
drivers/md/dm-core.h
View File

@ -250,12 +250,11 @@ struct dm_io {
struct mapped_device *md;
struct bio *orig_bio;
blk_status_t status;
spinlock_t lock;
unsigned long start_time;
void *data;
struct hlist_node node;
struct task_struct *map_task;
spinlock_t startio_lock;
spinlock_t endio_lock;
struct dm_stats_aux stats_aux;
/* last member of dm_target_io is 'struct bio' */
struct dm_target_io tio;

11
drivers/md/dm.c
View File

@ -550,9 +550,9 @@ static void dm_start_io_acct(struct dm_io *io, struct bio *clone)
if (dm_io_flagged(io, DM_IO_ACCOUNTED))
return;
/* Can afford locking given DM_TIO_IS_DUPLICATE_BIO */
spin_lock_irqsave(&io->startio_lock, flags);
spin_lock_irqsave(&io->lock, flags);
dm_io_set_flag(io, DM_IO_ACCOUNTED);
spin_unlock_irqrestore(&io->startio_lock, flags);
spin_unlock_irqrestore(&io->lock, flags);
}
__dm_start_io_acct(io, bio);
@ -584,8 +584,7 @@ static struct dm_io *alloc_io(struct mapped_device *md, struct bio *bio)
io->orig_bio = NULL;
io->md = md;
io->map_task = current;
spin_lock_init(&io->startio_lock);
spin_lock_init(&io->endio_lock);
spin_lock_init(&io->lock);
io->start_time = jiffies;
io->flags = 0;
@ -933,11 +932,11 @@ void dm_io_dec_pending(struct dm_io *io, blk_status_t error)
/* Push-back supersedes any I/O errors */
if (unlikely(error)) {
unsigned long flags;
spin_lock_irqsave(&io->endio_lock, flags);
spin_lock_irqsave(&io->lock, flags);
if (!(io->status == BLK_STS_DM_REQUEUE &&
__noflush_suspending(io->md)))
io->status = error;
spin_unlock_irqrestore(&io->endio_lock, flags);
spin_unlock_irqrestore(&io->lock, flags);
}
if (atomic_dec_and_test(&io->io_count))