Commit ab58a5a1 authored by Xiubo Li's avatar Xiubo Li Committed by Ilya Dryomov
Browse files

ceph: move to a dedicated slabcache for ceph_cap_snap 



There could be huge number of capsnaps around at any given time. On
x86_64 the structure is 248 bytes, which will be rounded up to 256 bytes
by kzalloc. Move this to a dedicated slabcache to save 8 bytes for each.

[ jlayton: use kmem_cache_zalloc ]

Signed-off-by: default avatarXiubo Li <xiubli@redhat.com>
Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent 6ddf5f16

fs/ceph/snap.c

+3 −2
Original line number Diff line number Diff line
@@ -482,7 +482,7 @@ static void ceph_queue_cap_snap(struct ceph_inode_info *ci) 
	struct ceph_buffer *old_blob = NULL;

	int used, dirty;



	capsnap = kzalloc(sizeof(*capsnap), GFP_NOFS);

	capsnap = kmem_cache_zalloc(ceph_cap_snap_cachep, GFP_NOFS);

	if (!capsnap) {

		pr_err("ENOMEM allocating ceph_cap_snap on %p\n", inode);

		return;
@@ -603,7 +603,8 @@ static void ceph_queue_cap_snap(struct ceph_inode_info *ci) 
	spin_unlock(&ci->i_ceph_lock);



	ceph_buffer_put(old_blob);

	kfree(capsnap);

	if (capsnap)

		kmem_cache_free(ceph_cap_snap_cachep, capsnap);

	ceph_put_snap_context(old_snapc);

}

fs/ceph/super.c

+7 −0
Original line number Diff line number Diff line
@@ -864,6 +864,7 @@ static void destroy_fs_client(struct ceph_fs_client *fsc) 
 */

struct kmem_cache *ceph_inode_cachep;

struct kmem_cache *ceph_cap_cachep;

struct kmem_cache *ceph_cap_snap_cachep;

struct kmem_cache *ceph_cap_flush_cachep;

struct kmem_cache *ceph_dentry_cachep;

struct kmem_cache *ceph_file_cachep;
@@ -892,6 +893,9 @@ static int __init init_caches(void) 
	ceph_cap_cachep = KMEM_CACHE(ceph_cap, SLAB_MEM_SPREAD);

	if (!ceph_cap_cachep)

		goto bad_cap;

	ceph_cap_snap_cachep = KMEM_CACHE(ceph_cap_snap, SLAB_MEM_SPREAD);

	if (!ceph_cap_snap_cachep)

		goto bad_cap_snap;

	ceph_cap_flush_cachep = KMEM_CACHE(ceph_cap_flush,

					   SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);

	if (!ceph_cap_flush_cachep)
@@ -931,6 +935,8 @@ static int __init init_caches(void) 
bad_dentry:

	kmem_cache_destroy(ceph_cap_flush_cachep);

bad_cap_flush:

	kmem_cache_destroy(ceph_cap_snap_cachep);

bad_cap_snap:

	kmem_cache_destroy(ceph_cap_cachep);

bad_cap:

	kmem_cache_destroy(ceph_inode_cachep);
@@ -947,6 +953,7 @@ static void destroy_caches(void) 


	kmem_cache_destroy(ceph_inode_cachep);

	kmem_cache_destroy(ceph_cap_cachep);

	kmem_cache_destroy(ceph_cap_snap_cachep);

	kmem_cache_destroy(ceph_cap_flush_cachep);

	kmem_cache_destroy(ceph_dentry_cachep);

	kmem_cache_destroy(ceph_file_cachep);

fs/ceph/super.h

+1 −1
Original line number Diff line number Diff line
@@ -230,7 +230,7 @@ static inline void ceph_put_cap_snap(struct ceph_cap_snap *capsnap) 
	if (refcount_dec_and_test(&capsnap->nref)) {

		if (capsnap->xattr_blob)

			ceph_buffer_put(capsnap->xattr_blob);

		kfree(capsnap);

		kmem_cache_free(ceph_cap_snap_cachep, capsnap);

	}

}

include/linux/ceph/libceph.h

+1 −0
Original line number Diff line number Diff line
@@ -284,6 +284,7 @@ DEFINE_RB_LOOKUP_FUNC(name, type, keyfld, nodefld) 


extern struct kmem_cache *ceph_inode_cachep;

extern struct kmem_cache *ceph_cap_cachep;

extern struct kmem_cache *ceph_cap_snap_cachep;

extern struct kmem_cache *ceph_cap_flush_cachep;

extern struct kmem_cache *ceph_dentry_cachep;

extern struct kmem_cache *ceph_file_cachep;