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dm cache: replace spin_lock_irqsave with spin_lock_irq
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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 they don't need to
push and pop the flags register.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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Mikulas Patocka authored and Mike Snitzer committed Nov 5, 2019
1 parent 235bc86 commit 26b924b
Showing 1 changed file with 28 additions and 49 deletions.
77 changes: 28 additions & 49 deletions drivers/md/dm-cache-target.c
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Original file line number Diff line number Diff line change
Expand Up @@ -74,22 +74,19 @@ static bool __iot_idle_for(struct io_tracker *iot, unsigned long jifs)
static bool iot_idle_for(struct io_tracker *iot, unsigned long jifs)
{
bool r;
unsigned long flags;

spin_lock_irqsave(&iot->lock, flags);
spin_lock_irq(&iot->lock);
r = __iot_idle_for(iot, jifs);
spin_unlock_irqrestore(&iot->lock, flags);
spin_unlock_irq(&iot->lock);

return r;
}

static void iot_io_begin(struct io_tracker *iot, sector_t len)
{
unsigned long flags;

spin_lock_irqsave(&iot->lock, flags);
spin_lock_irq(&iot->lock);
iot->in_flight += len;
spin_unlock_irqrestore(&iot->lock, flags);
spin_unlock_irq(&iot->lock);
}

static void __iot_io_end(struct io_tracker *iot, sector_t len)
Expand Down Expand Up @@ -172,7 +169,6 @@ static void __commit(struct work_struct *_ws)
{
struct batcher *b = container_of(_ws, struct batcher, commit_work);
blk_status_t r;
unsigned long flags;
struct list_head work_items;
struct work_struct *ws, *tmp;
struct continuation *k;
Expand All @@ -186,12 +182,12 @@ static void __commit(struct work_struct *_ws)
* We have to grab these before the commit_op to avoid a race
* condition.
*/
spin_lock_irqsave(&b->lock, flags);
spin_lock_irq(&b->lock);
list_splice_init(&b->work_items, &work_items);
bio_list_merge(&bios, &b->bios);
bio_list_init(&b->bios);
b->commit_scheduled = false;
spin_unlock_irqrestore(&b->lock, flags);
spin_unlock_irq(&b->lock);

r = b->commit_op(b->commit_context);

Expand Down Expand Up @@ -238,13 +234,12 @@ static void async_commit(struct batcher *b)

static void continue_after_commit(struct batcher *b, struct continuation *k)
{
unsigned long flags;
bool commit_scheduled;

spin_lock_irqsave(&b->lock, flags);
spin_lock_irq(&b->lock);
commit_scheduled = b->commit_scheduled;
list_add_tail(&k->ws.entry, &b->work_items);
spin_unlock_irqrestore(&b->lock, flags);
spin_unlock_irq(&b->lock);

if (commit_scheduled)
async_commit(b);
Expand All @@ -255,13 +250,12 @@ static void continue_after_commit(struct batcher *b, struct continuation *k)
*/
static void issue_after_commit(struct batcher *b, struct bio *bio)
{
unsigned long flags;
bool commit_scheduled;

spin_lock_irqsave(&b->lock, flags);
spin_lock_irq(&b->lock);
commit_scheduled = b->commit_scheduled;
bio_list_add(&b->bios, bio);
spin_unlock_irqrestore(&b->lock, flags);
spin_unlock_irq(&b->lock);

if (commit_scheduled)
async_commit(b);
Expand All @@ -273,12 +267,11 @@ static void issue_after_commit(struct batcher *b, struct bio *bio)
static void schedule_commit(struct batcher *b)
{
bool immediate;
unsigned long flags;

spin_lock_irqsave(&b->lock, flags);
spin_lock_irq(&b->lock);
immediate = !list_empty(&b->work_items) || !bio_list_empty(&b->bios);
b->commit_scheduled = true;
spin_unlock_irqrestore(&b->lock, flags);
spin_unlock_irq(&b->lock);

if (immediate)
async_commit(b);
Expand Down Expand Up @@ -630,23 +623,19 @@ static struct per_bio_data *init_per_bio_data(struct bio *bio)

static void defer_bio(struct cache *cache, struct bio *bio)
{
unsigned long flags;

spin_lock_irqsave(&cache->lock, flags);
spin_lock_irq(&cache->lock);
bio_list_add(&cache->deferred_bios, bio);
spin_unlock_irqrestore(&cache->lock, flags);
spin_unlock_irq(&cache->lock);

wake_deferred_bio_worker(cache);
}

static void defer_bios(struct cache *cache, struct bio_list *bios)
{
unsigned long flags;

spin_lock_irqsave(&cache->lock, flags);
spin_lock_irq(&cache->lock);
bio_list_merge(&cache->deferred_bios, bios);
bio_list_init(bios);
spin_unlock_irqrestore(&cache->lock, flags);
spin_unlock_irq(&cache->lock);

wake_deferred_bio_worker(cache);
}
Expand Down Expand Up @@ -756,46 +745,38 @@ static dm_dblock_t oblock_to_dblock(struct cache *cache, dm_oblock_t oblock)

static void set_discard(struct cache *cache, dm_dblock_t b)
{
unsigned long flags;

BUG_ON(from_dblock(b) >= from_dblock(cache->discard_nr_blocks));
atomic_inc(&cache->stats.discard_count);

spin_lock_irqsave(&cache->lock, flags);
spin_lock_irq(&cache->lock);
set_bit(from_dblock(b), cache->discard_bitset);
spin_unlock_irqrestore(&cache->lock, flags);
spin_unlock_irq(&cache->lock);
}

static void clear_discard(struct cache *cache, dm_dblock_t b)
{
unsigned long flags;

spin_lock_irqsave(&cache->lock, flags);
spin_lock_irq(&cache->lock);
clear_bit(from_dblock(b), cache->discard_bitset);
spin_unlock_irqrestore(&cache->lock, flags);
spin_unlock_irq(&cache->lock);
}

static bool is_discarded(struct cache *cache, dm_dblock_t b)
{
int r;
unsigned long flags;

spin_lock_irqsave(&cache->lock, flags);
spin_lock_irq(&cache->lock);
r = test_bit(from_dblock(b), cache->discard_bitset);
spin_unlock_irqrestore(&cache->lock, flags);
spin_unlock_irq(&cache->lock);

return r;
}

static bool is_discarded_oblock(struct cache *cache, dm_oblock_t b)
{
int r;
unsigned long flags;

spin_lock_irqsave(&cache->lock, flags);
spin_lock_irq(&cache->lock);
r = test_bit(from_dblock(oblock_to_dblock(cache, b)),
cache->discard_bitset);
spin_unlock_irqrestore(&cache->lock, flags);
spin_unlock_irq(&cache->lock);

return r;
}
Expand Down Expand Up @@ -827,17 +808,16 @@ static void remap_to_cache(struct cache *cache, struct bio *bio,

static void check_if_tick_bio_needed(struct cache *cache, struct bio *bio)
{
unsigned long flags;
struct per_bio_data *pb;

spin_lock_irqsave(&cache->lock, flags);
spin_lock_irq(&cache->lock);
if (cache->need_tick_bio && !op_is_flush(bio->bi_opf) &&
bio_op(bio) != REQ_OP_DISCARD) {
pb = get_per_bio_data(bio);
pb->tick = true;
cache->need_tick_bio = false;
}
spin_unlock_irqrestore(&cache->lock, flags);
spin_unlock_irq(&cache->lock);
}

static void __remap_to_origin_clear_discard(struct cache *cache, struct bio *bio,
Expand Down Expand Up @@ -1889,17 +1869,16 @@ static void process_deferred_bios(struct work_struct *ws)
{
struct cache *cache = container_of(ws, struct cache, deferred_bio_worker);

unsigned long flags;
bool commit_needed = false;
struct bio_list bios;
struct bio *bio;

bio_list_init(&bios);

spin_lock_irqsave(&cache->lock, flags);
spin_lock_irq(&cache->lock);
bio_list_merge(&bios, &cache->deferred_bios);
bio_list_init(&cache->deferred_bios);
spin_unlock_irqrestore(&cache->lock, flags);
spin_unlock_irq(&cache->lock);

while ((bio = bio_list_pop(&bios))) {
if (bio->bi_opf & REQ_PREFLUSH)
Expand Down

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