[dm-devel] [PATCH] dm-clone: replace spin_lock_irqsave with spin_lock_irq
Mikulas Patocka
mpatocka at redhat.com
Fri Oct 4 14:17:37 UTC 2019
If we are in a place where it is known that interrupts are enabled,
functions spin_lock_irq/spin_unlock_irq should be used instead of
spin_lock_irqsave/spin_unlock_irqrestore.
spin_lock_irq and spin_unlock_irq are faster because the don't need to
push and pop the flags register.
Signed-off-by: Mikulas Patocka <mpatocka at redhat.com>
---
drivers/md/dm-clone-metadata.c | 29 ++++++++++++-----------------
drivers/md/dm-clone-target.c | 28 ++++++++++++----------------
2 files changed, 24 insertions(+), 33 deletions(-)
Index: linux-2.6/drivers/md/dm-clone-metadata.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-clone-metadata.c 2019-10-04 14:49:46.000000000 +0200
+++ linux-2.6/drivers/md/dm-clone-metadata.c 2019-10-04 16:07:49.000000000 +0200
@@ -712,7 +712,7 @@ static int __metadata_commit(struct dm_c
static int __flush_dmap(struct dm_clone_metadata *cmd, struct dirty_map *dmap)
{
int r;
- unsigned long word, flags;
+ unsigned long word;
word = 0;
do {
@@ -736,9 +736,9 @@ static int __flush_dmap(struct dm_clone_
return r;
/* Update the changed flag */
- spin_lock_irqsave(&cmd->bitmap_lock, flags);
+ spin_lock_irq(&cmd->bitmap_lock);
dmap->changed = 0;
- spin_unlock_irqrestore(&cmd->bitmap_lock, flags);
+ spin_unlock_irq(&cmd->bitmap_lock);
return 0;
}
@@ -746,7 +746,6 @@ static int __flush_dmap(struct dm_clone_
int dm_clone_metadata_commit(struct dm_clone_metadata *cmd)
{
int r = -EPERM;
- unsigned long flags;
struct dirty_map *dmap, *next_dmap;
down_write(&cmd->lock);
@@ -770,9 +769,9 @@ int dm_clone_metadata_commit(struct dm_c
}
/* Swap dirty bitmaps */
- spin_lock_irqsave(&cmd->bitmap_lock, flags);
+ spin_lock_irq(&cmd->bitmap_lock);
cmd->current_dmap = next_dmap;
- spin_unlock_irqrestore(&cmd->bitmap_lock, flags);
+ spin_unlock_irq(&cmd->bitmap_lock);
/*
* No one is accessing the old dirty bitmap anymore, so we can flush
@@ -817,9 +816,9 @@ int dm_clone_cond_set_range(struct dm_cl
{
int r = 0;
struct dirty_map *dmap;
- unsigned long word, region_nr, flags;
+ unsigned long word, region_nr;
- spin_lock_irqsave(&cmd->bitmap_lock, flags);
+ spin_lock_irq(&cmd->bitmap_lock);
if (cmd->read_only) {
r = -EPERM;
@@ -836,7 +835,7 @@ int dm_clone_cond_set_range(struct dm_cl
}
}
out:
- spin_unlock_irqrestore(&cmd->bitmap_lock, flags);
+ spin_unlock_irq(&cmd->bitmap_lock);
return r;
}
@@ -903,13 +902,11 @@ out:
void dm_clone_metadata_set_read_only(struct dm_clone_metadata *cmd)
{
- unsigned long flags;
-
down_write(&cmd->lock);
- spin_lock_irqsave(&cmd->bitmap_lock, flags);
+ spin_lock_irq(&cmd->bitmap_lock);
cmd->read_only = 1;
- spin_unlock_irqrestore(&cmd->bitmap_lock, flags);
+ spin_unlock_irq(&cmd->bitmap_lock);
if (!cmd->fail_io)
dm_bm_set_read_only(cmd->bm);
@@ -919,13 +916,11 @@ void dm_clone_metadata_set_read_only(str
void dm_clone_metadata_set_read_write(struct dm_clone_metadata *cmd)
{
- unsigned long flags;
-
down_write(&cmd->lock);
- spin_lock_irqsave(&cmd->bitmap_lock, flags);
+ spin_lock_irq(&cmd->bitmap_lock);
cmd->read_only = 0;
- spin_unlock_irqrestore(&cmd->bitmap_lock, flags);
+ spin_unlock_irq(&cmd->bitmap_lock);
if (!cmd->fail_io)
dm_bm_set_read_write(cmd->bm);
Index: linux-2.6/drivers/md/dm-clone-target.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-clone-target.c 2019-10-04 14:49:46.000000000 +0200
+++ linux-2.6/drivers/md/dm-clone-target.c 2019-10-04 16:03:39.000000000 +0200
@@ -332,8 +332,6 @@ static void submit_bios(struct bio_list
*/
static void issue_bio(struct clone *clone, struct bio *bio)
{
- unsigned long flags;
-
if (!bio_triggers_commit(clone, bio)) {
generic_make_request(bio);
return;
@@ -352,9 +350,9 @@ static void issue_bio(struct clone *clon
* Batch together any bios that trigger commits and then issue a single
* commit for them in process_deferred_flush_bios().
*/
- spin_lock_irqsave(&clone->lock, flags);
+ spin_lock_irq(&clone->lock);
bio_list_add(&clone->deferred_flush_bios, bio);
- spin_unlock_irqrestore(&clone->lock, flags);
+ spin_unlock_irq(&clone->lock);
wake_worker(clone);
}
@@ -469,7 +467,7 @@ static void complete_discard_bio(struct
static void process_discard_bio(struct clone *clone, struct bio *bio)
{
- unsigned long rs, re, flags;
+ unsigned long rs, re;
bio_region_range(clone, bio, &rs, &re);
BUG_ON(re > clone->nr_regions);
@@ -501,9 +499,9 @@ static void process_discard_bio(struct c
/*
* Defer discard processing.
*/
- spin_lock_irqsave(&clone->lock, flags);
+ spin_lock_irq(&clone->lock);
bio_list_add(&clone->deferred_discard_bios, bio);
- spin_unlock_irqrestore(&clone->lock, flags);
+ spin_unlock_irq(&clone->lock);
wake_worker(clone);
}
@@ -1140,13 +1138,13 @@ static void process_deferred_discards(st
int r = -EPERM;
struct bio *bio;
struct blk_plug plug;
- unsigned long rs, re, flags;
+ unsigned long rs, re;
struct bio_list discards = BIO_EMPTY_LIST;
- spin_lock_irqsave(&clone->lock, flags);
+ spin_lock_irq(&clone->lock);
bio_list_merge(&discards, &clone->deferred_discard_bios);
bio_list_init(&clone->deferred_discard_bios);
- spin_unlock_irqrestore(&clone->lock, flags);
+ spin_unlock_irq(&clone->lock);
if (bio_list_empty(&discards))
return;
@@ -1176,13 +1174,12 @@ out:
static void process_deferred_bios(struct clone *clone)
{
- unsigned long flags;
struct bio_list bios = BIO_EMPTY_LIST;
- spin_lock_irqsave(&clone->lock, flags);
+ spin_lock_irq(&clone->lock);
bio_list_merge(&bios, &clone->deferred_bios);
bio_list_init(&clone->deferred_bios);
- spin_unlock_irqrestore(&clone->lock, flags);
+ spin_unlock_irq(&clone->lock);
if (bio_list_empty(&bios))
return;
@@ -1193,7 +1190,6 @@ static void process_deferred_bios(struct
static void process_deferred_flush_bios(struct clone *clone)
{
struct bio *bio;
- unsigned long flags;
struct bio_list bios = BIO_EMPTY_LIST;
struct bio_list bio_completions = BIO_EMPTY_LIST;
@@ -1201,13 +1197,13 @@ static void process_deferred_flush_bios(
* If there are any deferred flush bios, we must commit the metadata
* before issuing them or signaling their completion.
*/
- spin_lock_irqsave(&clone->lock, flags);
+ spin_lock_irq(&clone->lock);
bio_list_merge(&bios, &clone->deferred_flush_bios);
bio_list_init(&clone->deferred_flush_bios);
bio_list_merge(&bio_completions, &clone->deferred_flush_completions);
bio_list_init(&clone->deferred_flush_completions);
- spin_unlock_irqrestore(&clone->lock, flags);
+ spin_unlock_irq(&clone->lock);
if (bio_list_empty(&bios) && bio_list_empty(&bio_completions) &&
!(dm_clone_changed_this_transaction(clone->cmd) && need_commit_due_to_time(clone)))
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