Btrfs: use a slab for the free space entries

Since we alloc/free free space entries a whole lot, lets use a slab to keep
track of them.  This makes some of my tests slightly faster.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>

1 files changed, 18 insertions, 16 deletions

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index a0390657451b..0282033041e1 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -393,7 +393,8 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
                                 break;
 
                         need_loop = 1;
-                        e = kzalloc(sizeof(struct btrfs_free_space), GFP_NOFS);
+                        e = kmem_cache_zalloc(btrfs_free_space_cachep,
+                                              GFP_NOFS);
                         if (!e) {
                                 kunmap(page);
                                 unlock_page(page);
@@ -405,7 +406,7 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
                         e->bytes = le64_to_cpu(entry->bytes);
                         if (!e->bytes) {
                                 kunmap(page);
-                                kfree(e);
+                                kmem_cache_free(btrfs_free_space_cachep, e);
                                 unlock_page(page);
                                 page_cache_release(page);
                                 goto free_cache;
@@ -420,7 +421,8 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
                                 e->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
                                 if (!e->bitmap) {
                                         kunmap(page);
-                                        kfree(e);
+                                        kmem_cache_free(
+                                                btrfs_free_space_cachep, e);
                                         unlock_page(page);
                                         page_cache_release(page);
                                         goto free_cache;
@@ -1187,7 +1189,7 @@ static void free_bitmap(struct btrfs_block_group_cache *block_group,
 {
         unlink_free_space(block_group, bitmap_info);
         kfree(bitmap_info->bitmap);
-        kfree(bitmap_info);
+        kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
         block_group->total_bitmaps--;
         recalculate_thresholds(block_group);
 }
@@ -1342,8 +1344,8 @@ new_bitmap:
 
                 /* no pre-allocated info, allocate a new one */
                 if (!info) {
-                        info = kzalloc(sizeof(struct btrfs_free_space),
-                                       GFP_NOFS);
+                        info = kmem_cache_zalloc(btrfs_free_space_cachep,
+                                                 GFP_NOFS);
                         if (!info) {
                                 spin_lock(&block_group->tree_lock);
                                 ret = -ENOMEM;
@@ -1365,7 +1367,7 @@ out:
         if (info) {
                 if (info->bitmap)
                         kfree(info->bitmap);
-                kfree(info);
+                kmem_cache_free(btrfs_free_space_cachep, info);
         }
 
         return ret;
@@ -1398,7 +1400,7 @@ bool try_merge_free_space(struct btrfs_block_group_cache *block_group,
                 else
                         __unlink_free_space(block_group, right_info);
                 info->bytes += right_info->bytes;
-                kfree(right_info);
+                kmem_cache_free(btrfs_free_space_cachep, right_info);
                 merged = true;
         }
 
@@ -1410,7 +1412,7 @@ bool try_merge_free_space(struct btrfs_block_group_cache *block_group,
                         __unlink_free_space(block_group, left_info);
                 info->offset = left_info->offset;
                 info->bytes += left_info->bytes;
-                kfree(left_info);
+                kmem_cache_free(btrfs_free_space_cachep, left_info);
                 merged = true;
         }
 
@@ -1423,7 +1425,7 @@ int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
         struct btrfs_free_space *info;
         int ret = 0;
 
-        info = kzalloc(sizeof(struct btrfs_free_space), GFP_NOFS);
+        info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
         if (!info)
                 return -ENOMEM;
 
@@ -1450,7 +1452,7 @@ int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
 link:
         ret = link_free_space(block_group, info);
         if (ret)
-                kfree(info);
+                kmem_cache_free(btrfs_free_space_cachep, info);
 out:
         spin_unlock(&block_group->tree_lock);
 
@@ -1520,7 +1522,7 @@ again:
                         kfree(info->bitmap);
                         block_group->total_bitmaps--;
                 }
-                kfree(info);
+                kmem_cache_free(btrfs_free_space_cachep, info);
                 goto out_lock;
         }
 
@@ -1556,7 +1558,7 @@ again:
                         /* the hole we're creating ends at the end
                          * of the info struct, just free the info
                          */
-                        kfree(info);
+                        kmem_cache_free(btrfs_free_space_cachep, info);
                 }
                 spin_unlock(&block_group->tree_lock);
 
@@ -1689,7 +1691,7 @@ void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
                 unlink_free_space(block_group, info);
                 if (info->bitmap)
                         kfree(info->bitmap);
-                kfree(info);
+                kmem_cache_free(btrfs_free_space_cachep, info);
                 if (need_resched()) {
                         spin_unlock(&block_group->tree_lock);
                         cond_resched();
@@ -1722,7 +1724,7 @@ u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
                 entry->offset += bytes;
                 entry->bytes -= bytes;
                 if (!entry->bytes)
-                        kfree(entry);
+                        kmem_cache_free(btrfs_free_space_cachep, entry);
                 else
                         link_free_space(block_group, entry);
         }
@@ -1884,7 +1886,7 @@ out:
         block_group->free_space -= bytes;
         if (entry->bytes == 0) {
                 block_group->free_extents--;
-                kfree(entry);
+                kmem_cache_free(btrfs_free_space_cachep, entry);
         }
 
         spin_unlock(&block_group->tree_lock);