Merge "zram: don't grab mutex in zram_slot_free_noity" (8d12169b) · Commits · e / devices / samsung / android_kernel_samsung_msm8916

drivers/staging/zram/zram_drv.c

+57 −3

Original line number	Diff line number	Diff line
		@@ -440,6 +440,14 @@ static int zram_bvec_write(struct zram zram, struct bio_vec bvec, u32 index,
		goto out;
		}

		/*
		* zram_slot_free_notify could miss free so that let's
		* double check.
		*/
		if (unlikely(meta->table[index].handle \|\|
		zram_test_flag(meta, index, ZRAM_ZERO)))
		zram_free_page(zram, index);

		ret = lzo1x_1_compress(uncmem, PAGE_SIZE, src, &clen,
		meta->compress_workmem);

		@@ -505,6 +513,20 @@ 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)
		{
		@@ -512,10 +534,12 @@ static int zram_bvec_rw(struct zram zram, struct bio_vec bvec, u32 index,

		if (rw == READ) {
		down_read(&zram->lock);
		handle_pending_slot_free(zram);
		ret = zram_bvec_read(zram, bvec, index, offset, bio);
		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);
		}
		@@ -528,6 +552,8 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity)
		size_t index;
		struct zram_meta *meta;

		flush_work(&zram->free_work);

		down_write(&zram->init_lock);
		if (!zram->init_done) {
		up_write(&zram->init_lock);
		@@ -722,16 +748,40 @@ 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;

		zram = bdev->bd_disk->private_data;
		down_write(&zram->lock);
		zram_free_page(zram, index);
		up_write(&zram->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 = {
		@@ -778,6 +828,10 @@ 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",

drivers/staging/zram/zram_drv.h

+10 −0

Original line number	Diff line number	Diff line
		@@ -94,11 +94,20 @@ 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, table,
		* 32bit stat counters against concurrent
		* notifications, 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;
		@@ -109,6 +118,7 @@ struct zram {
		* we can store in a disk.
		*/
		u64 disksize; /* bytes */
		spinlock_t slot_free_lock;

		struct zram_stats stats;
		};