Commit 6352b91d authored by Miao Xie's avatar Miao Xie Committed by Chris Mason
Browse files

Btrfs: use a slab for ordered extents allocation 



The ordered extent allocation is in the fast path of the IO, so use a slab
to improve the speed of the allocation.

 "Size of the struct is 280, so this will fall into the size-512 bucket,
  giving 8 objects per page, while own slab will pack 14 objects into a page.

  Another benefit I see is to check for leaked objects when the module is
  removed (and the cache destroy takes place)."
						-- David Sterba

Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
parent b9a8cc5b

fs/btrfs/ordered-data.c

+21 −2
Original line number Diff line number Diff line
@@ -25,6 +25,8 @@ 
#include "btrfs_inode.h"

#include "extent_io.h"



static struct kmem_cache *btrfs_ordered_extent_cache;



static u64 entry_end(struct btrfs_ordered_extent *entry)

{

	if (entry->file_offset + entry->len < entry->file_offset)
@@ -187,7 +189,7 @@ static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset, 
	struct btrfs_ordered_extent *entry;



	tree = &BTRFS_I(inode)->ordered_tree;

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

	entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);

	if (!entry)

		return -ENOMEM;
@@ -421,7 +423,7 @@ void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry) 
			list_del(&sum->list);

			kfree(sum);

		}

		kfree(entry);

		kmem_cache_free(btrfs_ordered_extent_cache, entry);

	}

}
@@ -958,3 +960,20 @@ void btrfs_add_ordered_operation(struct btrfs_trans_handle *trans, 
	}

	spin_unlock(&root->fs_info->ordered_extent_lock);

}



int __init ordered_data_init(void)

{

	btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",

				     sizeof(struct btrfs_ordered_extent), 0,

				     SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,

				     NULL);

	if (!btrfs_ordered_extent_cache)

		return -ENOMEM;

	return 0;

}



void ordered_data_exit(void)

{

	if (btrfs_ordered_extent_cache)

		kmem_cache_destroy(btrfs_ordered_extent_cache);

}

fs/btrfs/ordered-data.h

+2 −0
Original line number Diff line number Diff line
@@ -192,4 +192,6 @@ void btrfs_add_ordered_operation(struct btrfs_trans_handle *trans, 
				 struct inode *inode);

void btrfs_wait_ordered_extents(struct btrfs_root *root,

				int nocow_only, int delay_iput);

int __init ordered_data_init(void);

void ordered_data_exit(void);

#endif

fs/btrfs/super.c

+8 −1
Original line number Diff line number Diff line
@@ -1620,10 +1620,14 @@ static int __init init_btrfs_fs(void) 
	if (err)

		goto free_extent_io;



	err = btrfs_delayed_inode_init();

	err = ordered_data_init();

	if (err)

		goto free_extent_map;



	err = btrfs_delayed_inode_init();

	if (err)

		goto free_ordered_data;



	err = btrfs_interface_init();

	if (err)

		goto free_delayed_inode;
@@ -1641,6 +1645,8 @@ unregister_ioctl: 
	btrfs_interface_exit();

free_delayed_inode:

	btrfs_delayed_inode_exit();

free_ordered_data:

	ordered_data_exit();

free_extent_map:

	extent_map_exit();

free_extent_io:
@@ -1657,6 +1663,7 @@ static void __exit exit_btrfs_fs(void) 
{

	btrfs_destroy_cachep();

	btrfs_delayed_inode_exit();

	ordered_data_exit();

	extent_map_exit();

	extent_io_exit();

	btrfs_interface_exit();

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