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Date: Mon, 13 Jan 2014 20:19:01 +0900
From: Minchan Kim <minchan@...nel.org>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org, Nitin Gupta <ngupta@...are.org>,
Jerome Marchand <jmarchan@...hat.com>,
Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
Minchan Kim <minchan@...nel.org>
Subject: [PATCH 6/7] zram: remove workqueue for freeing removed pending slot
[1] 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.
[1] a0c516c, zram: don't grab mutex in zram_slot_free_noity
Signed-off-by: Minchan Kim <minchan@...nel.org>
---
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 24e6426..f1a3c95 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -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;
- 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 c3f453f..d876300 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;
};
--
1.8.4.3
--
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