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: Miao Xie <miaox@cn.fujitsu.com>
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index cd8ecb7..e2b3d99 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -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 @@
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 @@
list_del(&sum->list);
kfree(sum);
}
- kfree(entry);
+ kmem_cache_free(btrfs_ordered_extent_cache, entry);
}
}
@@ -958,3 +960,20 @@
}
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);
+}