The ordered tree used to need a mutex, but currently all we use it for is to protect the rb_tree, and a spin_lock is just fine for that. Using a spin_lock instead makes dbench run a little faster, 58 mb/s instead of 51 mb/s, and have less latency, 3445.138 ms instead of 3820.633 ms.
Signed-off-by: Josef Bacik <[email protected]> --- fs/btrfs/ordered-data.c | 32 ++++++++++++++++---------------- fs/btrfs/ordered-data.h | 4 ++-- 2 files changed, 18 insertions(+), 18 deletions(-) diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c index c44054b..724d73f 100644 --- a/fs/btrfs/ordered-data.c +++ b/fs/btrfs/ordered-data.c @@ -174,7 +174,6 @@ int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset, if (!entry) return -ENOMEM; - mutex_lock(&tree->mutex); entry->file_offset = file_offset; entry->start = start; entry->len = len; @@ -190,16 +189,17 @@ int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset, INIT_LIST_HEAD(&entry->list); INIT_LIST_HEAD(&entry->root_extent_list); + spin_lock(&tree->lock); node = tree_insert(&tree->tree, file_offset, &entry->rb_node); BUG_ON(node); + spin_unlock(&tree->lock); spin_lock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock); list_add_tail(&entry->root_extent_list, &BTRFS_I(inode)->root->fs_info->ordered_extents); spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock); - mutex_unlock(&tree->mutex); BUG_ON(node); return 0; } @@ -216,9 +216,9 @@ int btrfs_add_ordered_sum(struct inode *inode, struct btrfs_ordered_inode_tree *tree; tree = &BTRFS_I(inode)->ordered_tree; - mutex_lock(&tree->mutex); + spin_lock(&tree->lock); list_add_tail(&sum->list, &entry->list); - mutex_unlock(&tree->mutex); + spin_unlock(&tree->lock); return 0; } @@ -241,7 +241,7 @@ int btrfs_dec_test_ordered_pending(struct inode *inode, int ret; tree = &BTRFS_I(inode)->ordered_tree; - mutex_lock(&tree->mutex); + spin_lock(&tree->lock); node = tree_search(tree, file_offset); if (!node) { ret = 1; @@ -269,7 +269,7 @@ out: *cached = entry; atomic_inc(&entry->refs); } - mutex_unlock(&tree->mutex); + spin_unlock(&tree->lock); return ret == 0; } @@ -345,9 +345,9 @@ int btrfs_remove_ordered_extent(struct inode *inode, int ret; tree = &BTRFS_I(inode)->ordered_tree; - mutex_lock(&tree->mutex); + spin_lock(&tree->lock); ret = __btrfs_remove_ordered_extent(inode, entry); - mutex_unlock(&tree->mutex); + spin_unlock(&tree->lock); wake_up(&entry->wait); return ret; @@ -572,7 +572,7 @@ struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode, struct btrfs_ordered_extent *entry = NULL; tree = &BTRFS_I(inode)->ordered_tree; - mutex_lock(&tree->mutex); + spin_lock(&tree->lock); node = tree_search(tree, file_offset); if (!node) goto out; @@ -583,7 +583,7 @@ struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode, if (entry) atomic_inc(&entry->refs); out: - mutex_unlock(&tree->mutex); + spin_unlock(&tree->lock); return entry; } @@ -599,7 +599,7 @@ btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset) struct btrfs_ordered_extent *entry = NULL; tree = &BTRFS_I(inode)->ordered_tree; - mutex_lock(&tree->mutex); + spin_lock(&tree->lock); node = tree_search(tree, file_offset); if (!node) goto out; @@ -607,7 +607,7 @@ btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset) entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); atomic_inc(&entry->refs); out: - mutex_unlock(&tree->mutex); + spin_unlock(&tree->lock); return entry; } @@ -634,7 +634,7 @@ int btrfs_ordered_update_i_size(struct inode *inode, u64 offset, else offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize); - mutex_lock(&tree->mutex); + spin_lock(&tree->lock); disk_i_size = BTRFS_I(inode)->disk_i_size; /* truncate file */ @@ -740,7 +740,7 @@ out: */ if (ordered) __btrfs_remove_ordered_extent(inode, ordered); - mutex_unlock(&tree->mutex); + spin_unlock(&tree->lock); if (ordered) wake_up(&ordered->wait); return ret; @@ -767,7 +767,7 @@ int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, if (!ordered) return 1; - mutex_lock(&tree->mutex); + spin_lock(&tree->lock); list_for_each_entry_reverse(ordered_sum, &ordered->list, list) { if (disk_bytenr >= ordered_sum->bytenr) { num_sectors = ordered_sum->len / sectorsize; @@ -782,7 +782,7 @@ int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, } } out: - mutex_unlock(&tree->mutex); + spin_unlock(&tree->lock); btrfs_put_ordered_extent(ordered); return ret; } diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h index 398bfc6..d7f359a 100644 --- a/fs/btrfs/ordered-data.h +++ b/fs/btrfs/ordered-data.h @@ -21,7 +21,7 @@ /* one of these per inode */ struct btrfs_ordered_inode_tree { - struct mutex mutex; + spinlock_t lock; struct rb_root tree; struct rb_node *last; }; @@ -128,7 +128,7 @@ static inline int btrfs_ordered_sum_size(struct btrfs_root *root, static inline void btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t) { - mutex_init(&t->mutex); + spin_lock_init(&t->lock); t->tree.rb_node = NULL; t->last = NULL; } -- 1.6.6 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
