Btrfs: Throttle tuning

[linux-2.6-block.git] / fs / btrfs / transaction.c

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 52c5524896a3feb65efebecd1e49a064a58404bb..66af5140c8cef49b94997dc414ab65e1d9482663 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -124,17 +124,12 @@ static noinline int record_root_in_trans(struct btrfs_root *root)
        return 0;
 }
 
-struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
-                                            int num_blocks, int join)
+static void wait_current_trans(struct btrfs_root *root)
 {
-       struct btrfs_trans_handle *h =
-               kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
        struct btrfs_transaction *cur_trans;
-       int ret;
 
-       mutex_lock(&root->fs_info->trans_mutex);
        cur_trans = root->fs_info->running_transaction;
-       if (cur_trans && cur_trans->blocked && !join) {
+       if (cur_trans && cur_trans->blocked) {
                DEFINE_WAIT(wait);
                cur_trans->use_count++;
                while(1) {
@@ -154,6 +149,18 @@ struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
                }
                put_transaction(cur_trans);
        }
+}
+
+struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
+                                            int num_blocks, int join)
+{
+       struct btrfs_trans_handle *h =
+               kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
+       int ret;
+
+       mutex_lock(&root->fs_info->trans_mutex);
+       if (!join)
+               wait_current_trans(root);
        ret = join_transaction(root);
        BUG_ON(ret);
 
@@ -200,7 +207,7 @@ static noinline int wait_for_commit(struct btrfs_root *root,
        return 0;
 }
 
-void btrfs_throttle(struct btrfs_root *root)
+static void throttle_on_drops(struct btrfs_root *root)
 {
        struct btrfs_fs_info *info = root->fs_info;
 
@@ -223,19 +230,28 @@ harder:
                } while (thr == atomic_read(&info->throttle_gen));
 
                if (harder_count < 5 &&
-                   info->total_ref_cache_size > 5 * 1024 * 1024) {
+                   info->total_ref_cache_size > 1 * 1024 * 1024) {
                        harder_count++;
                        goto harder;
                }
 
                if (harder_count < 10 &&
-                   info->total_ref_cache_size > 10 * 1024 * 1024) {
+                   info->total_ref_cache_size > 5 * 1024 * 1024) {
                        harder_count++;
                        goto harder;
                }
        }
 }
 
+void btrfs_throttle(struct btrfs_root *root)
+{
+       mutex_lock(&root->fs_info->trans_mutex);
+       wait_current_trans(root);
+       mutex_unlock(&root->fs_info->trans_mutex);
+
+       throttle_on_drops(root);
+}
+
 static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
                          struct btrfs_root *root, int throttle)
 {
@@ -256,7 +272,7 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
        kmem_cache_free(btrfs_trans_handle_cachep, trans);
 
        if (throttle)
-               btrfs_throttle(root);
+               throttle_on_drops(root);
 
        return 0;
 }