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Btrfs: Bring back find_free_extent CPU usage optimizations

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Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
2008-03-24 15:02:03 -04:00
parent 6324fbf334
commit 7d1660d411
1 changed files with 12 additions and 8 deletions
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20
fs/btrfs/extent-tree.c
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@@ -182,9 +182,9 @@ static int noinline find_search_start(struct btrfs_root *root,
int ret; int ret;
struct btrfs_block_group_cache *cache = *cache_ret; struct btrfs_block_group_cache *cache = *cache_ret;
struct extent_io_tree *free_space_cache; struct extent_io_tree *free_space_cache;
struct extent_state *state;
u64 last; u64 last;
u64 start = 0; u64 start = 0;
u64 end = 0;
u64 cache_miss = 0; u64 cache_miss = 0;
u64 total_fs_bytes; u64 total_fs_bytes;
u64 search_start = *start_ret; u64 search_start = *start_ret;
@@ -205,30 +205,34 @@ again:
goto new_group; goto new_group;
} }
spin_lock_irq(&free_space_cache->lock);
state = find_first_extent_bit_state(free_space_cache, last, EXTENT_DIRTY);
while(1) { while(1) {
ret = find_first_extent_bit(&root->fs_info->free_space_cache, if (!state) {
last, &start, &end, EXTENT_DIRTY);
if (ret) {
if (!cache_miss) if (!cache_miss)
cache_miss = last; cache_miss = last;
spin_unlock_irq(&free_space_cache->lock);
goto new_group; goto new_group;
} }
start = max(last, start); start = max(last, state->start);
last = end + 1; last = state->end + 1;
if (last - start < num) { if (last - start < num) {
if (last == cache->key.objectid + cache->key.offset) if (last == cache->key.objectid + cache->key.offset)
cache_miss = start; cache_miss = start;
do {
state = extent_state_next(state);
} while(state && !(state->state & EXTENT_DIRTY));
continue; continue;
} }
spin_unlock_irq(&free_space_cache->lock);
if (start + num > cache->key.objectid + cache->key.offset) if (start + num > cache->key.objectid + cache->key.offset)
goto new_group; goto new_group;
if (start + num > total_fs_bytes) if (start + num > total_fs_bytes)
goto new_group; goto new_group;
*start_ret = start; *start_ret = start;
return 0; return 0;
} } out:
out:
cache = btrfs_lookup_block_group(root->fs_info, search_start); cache = btrfs_lookup_block_group(root->fs_info, search_start);
if (!cache) { if (!cache) {
printk("Unable to find block group for %Lu\n", search_start); printk("Unable to find block group for %Lu\n", search_start);