From f614a9f48dedd2b80d1dc8bae8094842fcdb39dd Mon Sep 17 00:00:00 2001 From: Minchan Kim Date: Thu, 30 Jan 2014 15:46:04 -0800 Subject: [PATCH] zram: remove workqueue for freeing removed pending slot Commit a0c516cbfc74 ("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 Cc: Nitin Gupta Tested-by: Sergey Senozhatsky Cc: Jerome Marchand Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/zram/zram_drv.c | 54 ++++------------------------------- drivers/block/zram/zram_drv.h | 10 ------- 2 files changed, 6 insertions(+), 58 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 24e6426cf258..f1a3c958d84b 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -522,20 +522,6 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, 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 @@ static void zram_make_request(struct request_queue *queue, struct bio *bio) 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; - atomic64_inc(&zram->stats.notify_free); - - free_rq = kmalloc(sizeof(struct zram_slot_free), GFP_ATOMIC); - if (!free_rq) - return; + meta = zram->meta; - free_rq->index = index; - add_slot_free(zram, free_rq); - schedule_work(&zram->free_work); + write_lock(&meta->tb_lock); + zram_free_page(zram, index); + write_unlock(&meta->tb_lock); + atomic64_inc(&zram->stats.notify_free); } 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", diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index c3f453f04974..d876300da6c9 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -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; }; -- GitLab