Commit 8e1f936b authored by Rusty Russell's avatar Rusty Russell Committed by Linus Torvalds
Browse files

mm: clean up and kernelify shrinker registration 



I can never remember what the function to register to receive VM pressure
is called.  I have to trace down from __alloc_pages() to find it.

It's called "set_shrinker()", and it needs Your Help.

1) Don't hide struct shrinker.  It contains no magic.
2) Don't allocate "struct shrinker".  It's not helpful.
3) Call them "register_shrinker" and "unregister_shrinker".
4) Call the function "shrink" not "shrinker".
5) Reduce the 17 lines of waffly comments to 13, but document it properly.

Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Cc: David Chinner <dgc@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5ad333eb

fs/dcache.c

+6 −1
Original line number Diff line number Diff line
@@ -883,6 +883,11 @@ static int shrink_dcache_memory(int nr, gfp_t gfp_mask) 
	return (dentry_stat.nr_unused / 100) * sysctl_vfs_cache_pressure;

}



static struct shrinker dcache_shrinker = {

	.shrink = shrink_dcache_memory,

	.seeks = DEFAULT_SEEKS,

};



/**

 * d_alloc	-	allocate a dcache entry

 * @parent: parent of entry to allocate
@@ -2115,7 +2120,7 @@ static void __init dcache_init(unsigned long mempages) 
	dentry_cache = KMEM_CACHE(dentry,

		SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|SLAB_MEM_SPREAD);

	

	set_shrinker(DEFAULT_SEEKS, shrink_dcache_memory);

	register_shrinker(&dcache_shrinker);



	/* Hash may have been set up in dcache_init_early */

	if (!hashdist)

fs/dquot.c

+6 −1
Original line number Diff line number Diff line
@@ -538,6 +538,11 @@ static int shrink_dqcache_memory(int nr, gfp_t gfp_mask) 
	return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure;

}



static struct shrinker dqcache_shrinker = {

	.shrink = shrink_dqcache_memory,

	.seeks = DEFAULT_SEEKS,

};



/*

 * Put reference to dquot

 * NOTE: If you change this function please check whether dqput_blocks() works right...
@@ -1870,7 +1875,7 @@ static int __init dquot_init(void) 
	printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",

			nr_hash, order, (PAGE_SIZE << order));



	set_shrinker(DEFAULT_SEEKS, shrink_dqcache_memory);

	register_shrinker(&dqcache_shrinker);



	return 0;

}

fs/inode.c

+6 −1
Original line number Diff line number Diff line
@@ -462,6 +462,11 @@ static int shrink_icache_memory(int nr, gfp_t gfp_mask) 
	return (inodes_stat.nr_unused / 100) * sysctl_vfs_cache_pressure;

}



static struct shrinker icache_shrinker = {

	.shrink = shrink_icache_memory,

	.seeks = DEFAULT_SEEKS,

};



static void __wait_on_freeing_inode(struct inode *inode);

/*

 * Called with the inode lock held.
@@ -1385,7 +1390,7 @@ void __init inode_init(unsigned long mempages) 
					 SLAB_MEM_SPREAD),

					 init_once,

					 NULL);

	set_shrinker(DEFAULT_SEEKS, shrink_icache_memory);

	register_shrinker(&icache_shrinker);



	/* Hash may have been set up in inode_init_early */

	if (!hashdist)

fs/mbcache.c

+6 −3
Original line number Diff line number Diff line
@@ -100,7 +100,6 @@ struct mb_cache { 
static LIST_HEAD(mb_cache_list);

static LIST_HEAD(mb_cache_lru_list);

static DEFINE_SPINLOCK(mb_cache_spinlock);

static struct shrinker *mb_shrinker;



static inline int

mb_cache_indexes(struct mb_cache *cache)
@@ -118,6 +117,10 @@ mb_cache_indexes(struct mb_cache *cache) 


static int mb_cache_shrink_fn(int nr_to_scan, gfp_t gfp_mask);



static struct shrinker mb_cache_shrinker = {

	.shrink = mb_cache_shrink_fn,

	.seeks = DEFAULT_SEEKS,

};



static inline int

__mb_cache_entry_is_hashed(struct mb_cache_entry *ce)
@@ -662,13 +665,13 @@ mb_cache_entry_find_next(struct mb_cache_entry *prev, int index, 


static int __init init_mbcache(void)

{

	mb_shrinker = set_shrinker(DEFAULT_SEEKS, mb_cache_shrink_fn);

	register_shrinker(&mb_cache_shrinker);

	return 0;

}



static void __exit exit_mbcache(void)

{

	remove_shrinker(mb_shrinker);

	unregister_shrinker(&mb_cache_shrinker);

}



module_init(init_mbcache)

fs/nfs/super.c

+6 −4
Original line number Diff line number Diff line
@@ -300,7 +300,10 @@ static const struct super_operations nfs4_sops = { 
};

#endif



static struct shrinker *acl_shrinker;

static struct shrinker acl_shrinker = {

	.shrink		= nfs_access_cache_shrinker,

	.seeks		= DEFAULT_SEEKS,

};



/*

 * Register the NFS filesystems
@@ -321,7 +324,7 @@ int __init register_nfs_fs(void) 
	if (ret < 0)

		goto error_2;

#endif

	acl_shrinker = set_shrinker(DEFAULT_SEEKS, nfs_access_cache_shrinker);

	register_shrinker(&acl_shrinker);

	return 0;



#ifdef CONFIG_NFS_V4
@@ -339,8 +342,7 @@ error_0: 
 */

void __exit unregister_nfs_fs(void)

{

	if (acl_shrinker != NULL)

		remove_shrinker(acl_shrinker);

	unregister_shrinker(&acl_shrinker);

#ifdef CONFIG_NFS_V4

	unregister_filesystem(&nfs4_fs_type);

	nfs_unregister_sysctl();

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