Commit 1e84c4b7 authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm bufio: intelligently size dm_buffer_cache's buffer_trees 



Size the dm_buffer_cache's number of buffer_tree structs using
dm_num_hash_locks().

Signed-off-by: default avatarMike Snitzer <snitzer@kernel.org>
parent 36c18b86

drivers/md/dm-bufio.c

+8 −6
Original line number Diff line number Diff line
@@ -21,6 +21,8 @@ 
#include <linux/stacktrace.h>

#include <linux/jump_label.h>



#include "dm.h"



#define DM_MSG_PREFIX "bufio"



/*
@@ -379,8 +381,6 @@ struct dm_buffer { 
 * only enough to ensure get/put are threadsafe.

 */



#define NR_LOCKS 64



struct buffer_tree {

	struct rw_semaphore lock;

	struct rb_root root;
@@ -393,7 +393,7 @@ struct dm_buffer_cache { 
	 * on the locks.

	 */

	unsigned int num_locks;

	struct buffer_tree trees[NR_LOCKS];

	struct buffer_tree trees[];

};



static inline unsigned int cache_index(sector_t block, unsigned int num_locks)
@@ -976,7 +976,7 @@ struct dm_bufio_client { 
	 */

	unsigned long oldest_buffer;



	struct dm_buffer_cache cache;

	struct dm_buffer_cache cache; /* must be last member */

};



static DEFINE_STATIC_KEY_FALSE(no_sleep_enabled);
@@ -2422,6 +2422,7 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign 
					       unsigned int flags)

{

	int r;

	unsigned int num_locks;

	struct dm_bufio_client *c;

	char slab_name[27];
@@ -2431,12 +2432,13 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign 
		goto bad_client;

	}



	c = kzalloc(sizeof(*c), GFP_KERNEL);

	num_locks = dm_num_hash_locks();

	c = kzalloc(sizeof(*c) + (num_locks * sizeof(struct buffer_tree)), GFP_KERNEL);

	if (!c) {

		r = -ENOMEM;

		goto bad_client;

	}

	cache_init(&c->cache, NR_LOCKS);

	cache_init(&c->cache, num_locks);



	c->bdev = bdev;

	c->block_size = block_size;