From 7d1660d411a24f9b5a2f38e41c9896d7151c934f Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Mon, 24 Mar 2008 15:02:03 -0400 Subject: [PATCH] Btrfs: Bring back find_free_extent CPU usage optimizations Signed-off-by: Chris Mason --- fs/btrfs/extent-tree.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 15082b1087be..5e392804ab15 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -182,9 +182,9 @@ static int noinline find_search_start(struct btrfs_root *root, int ret; struct btrfs_block_group_cache *cache = *cache_ret; struct extent_io_tree *free_space_cache; + struct extent_state *state; u64 last; u64 start = 0; - u64 end = 0; u64 cache_miss = 0; u64 total_fs_bytes; u64 search_start = *start_ret; @@ -205,30 +205,34 @@ again: goto new_group; } + spin_lock_irq(&free_space_cache->lock); + state = find_first_extent_bit_state(free_space_cache, last, EXTENT_DIRTY); while(1) { - ret = find_first_extent_bit(&root->fs_info->free_space_cache, - last, &start, &end, EXTENT_DIRTY); - if (ret) { + if (!state) { if (!cache_miss) cache_miss = last; + spin_unlock_irq(&free_space_cache->lock); goto new_group; } - start = max(last, start); - last = end + 1; + start = max(last, state->start); + last = state->end + 1; if (last - start < num) { if (last == cache->key.objectid + cache->key.offset) cache_miss = start; + do { + state = extent_state_next(state); + } while(state && !(state->state & EXTENT_DIRTY)); continue; } + spin_unlock_irq(&free_space_cache->lock); if (start + num > cache->key.objectid + cache->key.offset) goto new_group; if (start + num > total_fs_bytes) goto new_group; *start_ret = start; return 0; - } -out: + } out: cache = btrfs_lookup_block_group(root->fs_info, search_start); if (!cache) { printk("Unable to find block group for %Lu\n", search_start); -- 2.20.1