Commit 1ab36c9d authored by Xiubo Li's avatar Xiubo Li Committed by Ilya Dryomov
Browse files

ceph: allocate capsnap memory outside of ceph_queue_cap_snap() 

This will reduce very possible but unnecessary frequently memory
allocate/free in this loop.

URL: https://tracker.ceph.com/issues/44100


Signed-off-by: default avatarXiubo Li <xiubli@redhat.com>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent 5ed91587

fs/ceph/snap.c

+28 −18
Original line number Diff line number Diff line
@@ -522,23 +522,15 @@ static bool has_new_snaps(struct ceph_snap_context *o, 
 * Caller must hold snap_rwsem for read (i.e., the realm topology won't

 * change).

 */

static void ceph_queue_cap_snap(struct ceph_inode_info *ci)

static void ceph_queue_cap_snap(struct ceph_inode_info *ci,

				struct ceph_cap_snap **pcapsnap)

{

	struct inode *inode = &ci->vfs_inode;

	struct ceph_cap_snap *capsnap;

	struct ceph_snap_context *old_snapc, *new_snapc;

	struct ceph_cap_snap *capsnap = *pcapsnap;

	struct ceph_buffer *old_blob = NULL;

	int used, dirty;



	capsnap = kmem_cache_zalloc(ceph_cap_snap_cachep, GFP_NOFS);

	if (!capsnap) {

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

		return;

	}

	capsnap->cap_flush.is_capsnap = true;

	INIT_LIST_HEAD(&capsnap->cap_flush.i_list);

	INIT_LIST_HEAD(&capsnap->cap_flush.g_list);



	spin_lock(&ci->i_ceph_lock);

	used = __ceph_caps_used(ci);

	dirty = __ceph_caps_dirty(ci);
@@ -595,9 +587,6 @@ static void ceph_queue_cap_snap(struct ceph_inode_info *ci) 
	     capsnap->need_flush ? "" : "no_flush");

	ihold(inode);



	refcount_set(&capsnap->nref, 1);

	INIT_LIST_HEAD(&capsnap->ci_item);



	capsnap->follows = old_snapc->seq;

	capsnap->issued = __ceph_caps_issued(ci, NULL);

	capsnap->dirty = dirty;
@@ -635,7 +624,7 @@ static void ceph_queue_cap_snap(struct ceph_inode_info *ci) 
		/* note mtime, size NOW. */

		__ceph_finish_cap_snap(ci, capsnap);

	}

	capsnap = NULL;

	*pcapsnap = NULL;

	old_snapc = NULL;



update_snapc:
@@ -651,8 +640,6 @@ static void ceph_queue_cap_snap(struct ceph_inode_info *ci) 
	spin_unlock(&ci->i_ceph_lock);



	ceph_buffer_put(old_blob);

	if (capsnap)

		kmem_cache_free(ceph_cap_snap_cachep, capsnap);

	ceph_put_snap_context(old_snapc);

}
@@ -720,6 +707,7 @@ static void queue_realm_cap_snaps(struct ceph_snap_realm *realm) 
{

	struct ceph_inode_info *ci;

	struct inode *lastinode = NULL;

	struct ceph_cap_snap *capsnap = NULL;



	dout("queue_realm_cap_snaps %p %llx inodes\n", realm, realm->ino);
@@ -731,12 +719,34 @@ static void queue_realm_cap_snaps(struct ceph_snap_realm *realm) 
		spin_unlock(&realm->inodes_with_caps_lock);

		iput(lastinode);

		lastinode = inode;

		ceph_queue_cap_snap(ci);



		/*

		 * Allocate the capsnap memory outside of ceph_queue_cap_snap()

		 * to reduce very possible but unnecessary frequently memory

		 * allocate/free in this loop.

		 */

		if (!capsnap) {

			capsnap = kmem_cache_zalloc(ceph_cap_snap_cachep, GFP_NOFS);

			if (!capsnap) {

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

				       inode);

				return;

			}

		}

		capsnap->cap_flush.is_capsnap = true;

		refcount_set(&capsnap->nref, 1);

		INIT_LIST_HEAD(&capsnap->cap_flush.i_list);

		INIT_LIST_HEAD(&capsnap->cap_flush.g_list);

		INIT_LIST_HEAD(&capsnap->ci_item);



		ceph_queue_cap_snap(ci, &capsnap);

		spin_lock(&realm->inodes_with_caps_lock);

	}

	spin_unlock(&realm->inodes_with_caps_lock);

	iput(lastinode);



	if (capsnap)

		kmem_cache_free(ceph_cap_snap_cachep, capsnap);

	dout("queue_realm_cap_snaps %p %llx done\n", realm, realm->ino);

}