Btrfs: allocate prelim_ref with a slab allocater

struct __prelim_ref is allocated and freed frequently when
walking backref tree, using slab allocater can not only
speed up allocating but also detect memory leaks.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index f3cb19114c957ffe273716241b09cfa80d1564be..0552a599b28f366ca2a4549458bfedeb8500fdd0 100644 (file)
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -119,6 +119,26 @@ struct __prelim_ref {
        u64 wanted_disk_byte;
 };
 
+static struct kmem_cache *btrfs_prelim_ref_cache;
+
+int __init btrfs_prelim_ref_init(void)
+{
+       btrfs_prelim_ref_cache = kmem_cache_create("btrfs_prelim_ref",
+                                       sizeof(struct __prelim_ref),
+                                       0,
+                                       SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
+                                       NULL);
+       if (!btrfs_prelim_ref_cache)
+               return -ENOMEM;
+       return 0;
+}
+
+void btrfs_prelim_ref_exit(void)
+{
+       if (btrfs_prelim_ref_cache)
+               kmem_cache_destroy(btrfs_prelim_ref_cache);
+}
+
 /*
  * the rules for all callers of this function are:
  * - obtaining the parent is the goal
@@ -165,7 +185,7 @@ static int __add_prelim_ref(struct list_head *head, u64 root_id,
 {
        struct __prelim_ref *ref;
 
-       ref = kmalloc(sizeof(*ref), gfp_mask);
+       ref = kmem_cache_alloc(btrfs_prelim_ref_cache, gfp_mask);
        if (!ref)
                return -ENOMEM;
 
@@ -368,7 +388,8 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,
 
                /* additional parents require new refs being added here */
                while ((node = ulist_next(parents, &uiter))) {
-                       new_ref = kmalloc(sizeof(*new_ref), GFP_NOFS);
+                       new_ref = kmem_cache_alloc(btrfs_prelim_ref_cache,
+                                                  GFP_NOFS);
                        if (!new_ref) {
                                ret = -ENOMEM;
                                goto out;
@@ -492,7 +513,7 @@ static void __merge_refs(struct list_head *head, int mode)
                        ref1->count += ref2->count;
 
                        list_del(&ref2->list);
-                       kfree(ref2);
+                       kmem_cache_free(btrfs_prelim_ref_cache, ref2);
                }
 
        }
@@ -955,7 +976,7 @@ again:
                        }
                }
                list_del(&ref->list);
-               kfree(ref);
+               kmem_cache_free(btrfs_prelim_ref_cache, ref);
        }
 
 out:
@@ -963,13 +984,13 @@ out:
        while (!list_empty(&prefs)) {
                ref = list_first_entry(&prefs, struct __prelim_ref, list);
                list_del(&ref->list);
-               kfree(ref);
+               kmem_cache_free(btrfs_prelim_ref_cache, ref);
        }
        while (!list_empty(&prefs_delayed)) {
                ref = list_first_entry(&prefs_delayed, struct __prelim_ref,
                                       list);
                list_del(&ref->list);
-               kfree(ref);
+               kmem_cache_free(btrfs_prelim_ref_cache, ref);
        }
 
        return ret;

diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h
index 8f2e767029322d2d3d0ac2baf996c3964e999cdf..a910b27a8ad9a025985b491f5b169fc3270999a0 100644 (file)
--- a/fs/btrfs/backref.h
+++ b/fs/btrfs/backref.h
@@ -72,4 +72,6 @@ int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid,
                          struct btrfs_inode_extref **ret_extref,
                          u64 *found_off);
 
+int __init btrfs_prelim_ref_init(void);
+void btrfs_prelim_ref_exit(void);
 #endif

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 4d5d0f3eb0d84cdeff84708162ec5034ff9b2540..3aab10ce63e84812b8e9c5a9250235db9b1bbe86 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -56,6 +56,7 @@
 #include "rcu-string.h"
 #include "dev-replace.h"
 #include "free-space-cache.h"
+#include "backref.h"
 #include "tests/btrfs-tests.h"
 
 #define CREATE_TRACE_POINTS
@@ -1810,6 +1811,10 @@ static int __init init_btrfs_fs(void)
        if (err)
                goto free_auto_defrag;
 
+       err = btrfs_prelim_ref_init();
+       if (err)
+               goto free_prelim_ref;
+
        err = btrfs_interface_init();
        if (err)
                goto free_delayed_ref;
@@ -1830,6 +1835,8 @@ static int __init init_btrfs_fs(void)
 
 unregister_ioctl:
        btrfs_interface_exit();
+free_prelim_ref:
+       btrfs_prelim_ref_exit();
 free_delayed_ref:
        btrfs_delayed_ref_exit();
 free_auto_defrag:
@@ -1856,6 +1863,7 @@ static void __exit exit_btrfs_fs(void)
        btrfs_delayed_ref_exit();
        btrfs_auto_defrag_exit();
        btrfs_delayed_inode_exit();
+       btrfs_prelim_ref_exit();
        ordered_data_exit();
        extent_map_exit();
        extent_io_exit();