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zram: remove workqueue for freeing removed pending slot 

Commit a0c516cbfc ("zram: don't grab mutex in zram_slot_free_noity")
introduced free request pending code to avoid scheduling by mutex under
spinlock and it was a mess which made code lenghty and increased
overhead.

Now, we don't need zram->lock any more to free slot so this patch
reverts it and then, tb_lock should protect it.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hifive-unleashed-5.1
Minchan Kim 2014-01-30 15:46:04 -08:00 committed by Linus Torvalds
parent 92967471b6
commit f614a9f48d
2 changed files with 6 additions and 58 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

54
drivers/block/zram/zram_drv.c
View File

@ -522,20 +522,6 @@ out:
return ret;
}
static void handle_pending_slot_free(struct zram *zram)
{
struct zram_slot_free *free_rq;
spin_lock(&zram->slot_free_lock);
while (zram->slot_free_rq) {
free_rq = zram->slot_free_rq;
zram->slot_free_rq = free_rq->next;
zram_free_page(zram, free_rq->index);
kfree(free_rq);
}
spin_unlock(&zram->slot_free_lock);
}
static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
int offset, struct bio *bio, int rw)
{
@ -547,7 +533,6 @@ static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
up_read(&zram->lock);
} else {
down_write(&zram->lock);
handle_pending_slot_free(zram);
ret = zram_bvec_write(zram, bvec, index, offset);
up_write(&zram->lock);
}
@ -566,8 +551,6 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity)
return;
}
flush_work(&zram->free_work);
meta = zram->meta;
zram->init_done = 0;
@ -769,40 +752,19 @@ error:
bio_io_error(bio);
}
static void zram_slot_free(struct work_struct *work)
{
struct zram *zram;
zram = container_of(work, struct zram, free_work);
down_write(&zram->lock);
handle_pending_slot_free(zram);
up_write(&zram->lock);
}
static void add_slot_free(struct zram *zram, struct zram_slot_free *free_rq)
{
spin_lock(&zram->slot_free_lock);
free_rq->next = zram->slot_free_rq;
zram->slot_free_rq = free_rq;
spin_unlock(&zram->slot_free_lock);
}
static void zram_slot_free_notify(struct block_device *bdev,
unsigned long index)
{
struct zram *zram;
struct zram_slot_free *free_rq;
struct zram_meta *meta;
zram = bdev->bd_disk->private_data;
meta = zram->meta;
write_lock(&meta->tb_lock);
zram_free_page(zram, index);
write_unlock(&meta->tb_lock);
atomic64_inc(&zram->stats.notify_free);
free_rq = kmalloc(sizeof(struct zram_slot_free), GFP_ATOMIC);
if (!free_rq)
return;
free_rq->index = index;
add_slot_free(zram, free_rq);
schedule_work(&zram->free_work);
}
static const struct block_device_operations zram_devops = {
@ -849,10 +811,6 @@ static int create_device(struct zram *zram, int device_id)
init_rwsem(&zram->lock);
init_rwsem(&zram->init_lock);
INIT_WORK(&zram->free_work, zram_slot_free);
spin_lock_init(&zram->slot_free_lock);
zram->slot_free_rq = NULL;
zram->queue = blk_alloc_queue(GFP_KERNEL);
if (!zram->queue) {
pr_err("Error allocating disk queue for device %d\n",

10
drivers/block/zram/zram_drv.h
View File

@ -90,20 +90,11 @@ struct zram_meta {
struct zs_pool *mem_pool;
};
struct zram_slot_free {
unsigned long index;
struct zram_slot_free *next;
};
struct zram {
struct zram_meta *meta;
struct rw_semaphore lock; /* protect compression buffers,
* reads and writes
*/
struct work_struct free_work; /* handle pending free request */
struct zram_slot_free *slot_free_rq; /* list head of free request */
struct request_queue *queue;
struct gendisk *disk;
int init_done;
@ -114,7 +105,6 @@ struct zram {
* we can store in a disk.
*/
u64 disksize; /* bytes */
spinlock_t slot_free_lock;
struct zram_stats stats;
};