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authorMike Snitzer <snitzer@redhat.com>2013-12-11 14:01:20 -0500
committerMike Snitzer <snitzer@redhat.com>2014-01-07 10:14:25 -0500
commitdaec338bbdaa96ba5b14c4777603e65ef74c769b (patch)
treea0798a5cddec99ad1bd7cda0b2b9a33164032e24 /drivers/md
parent8d30abff758b5f6c71343b7da6bb5de129a76c08 (diff)
downloadop-kernel-dev-daec338bbdaa96ba5b14c4777603e65ef74c769b.zip
op-kernel-dev-daec338bbdaa96ba5b14c4777603e65ef74c769b.tar.gz
dm thin: add mappings to end of prepared_* lists
Mappings could be processed in descending logical block order, particularly if buffered IO is used. This could adversely affect the latency of IO processing. Fix this by adding mappings to the end of the 'prepared_mappings' and 'prepared_discards' lists. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm-thin.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 1988019..efa3d42 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -535,7 +535,7 @@ static void __maybe_add_mapping(struct dm_thin_new_mapping *m)
struct pool *pool = m->tc->pool;
if (m->quiesced && m->prepared) {
- list_add(&m->list, &pool->prepared_mappings);
+ list_add_tail(&m->list, &pool->prepared_mappings);
wake_worker(pool);
}
}
@@ -1058,7 +1058,7 @@ static void process_discard(struct thin_c *tc, struct bio *bio)
if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list)) {
spin_lock_irqsave(&pool->lock, flags);
- list_add(&m->list, &pool->prepared_discards);
+ list_add_tail(&m->list, &pool->prepared_discards);
spin_unlock_irqrestore(&pool->lock, flags);
wake_worker(pool);
}
@@ -2919,7 +2919,7 @@ static int thin_endio(struct dm_target *ti, struct bio *bio, int err)
if (!list_empty(&work)) {
spin_lock_irqsave(&pool->lock, flags);
list_for_each_entry_safe(m, tmp, &work, list)
- list_add(&m->list, &pool->prepared_discards);
+ list_add_tail(&m->list, &pool->prepared_discards);
spin_unlock_irqrestore(&pool->lock, flags);
wake_worker(pool);
}
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