From d7fc640e6fed46932f7c74e14f9b58b8637c66cf Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Mon, 18 Feb 2008 12:12:38 -0500 Subject: [PATCH] Btrfs: Allocator improvements Reduce CPU time searching for free blocks by optimizing find_first_extent_bit Fix find_free_extent to make better use of the last_alloc hint. Before it was often finding blocks just before the hint. Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 2 +- fs/btrfs/extent-tree.c | 34 ++++++++++++++++++++++++---------- fs/btrfs/extent_io.c | 38 ++++++++++++++++++++++++++++++++++---- fs/btrfs/extent_io.h | 11 +++++++++++ 4 files changed, 70 insertions(+), 15 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 6f0825b617d1..88e21bdbc478 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -951,7 +951,7 @@ void btrfs_throttle(struct btrfs_root *root) void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr) { balance_dirty_pages_ratelimited_nr( - root->fs_info->btree_inode->i_mapping, 1); + root->fs_info->btree_inode->i_mapping, 1); } void btrfs_set_buffer_defrag(struct extent_buffer *buf) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index af5d4a085280..239e9d8669cb 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -188,9 +188,10 @@ static u64 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; int wrapped = 0; @@ -199,6 +200,8 @@ static u64 noinline find_search_start(struct btrfs_root *root, goto out; } total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy); + free_space_cache = &root->fs_info->free_space_cache; + again: ret = cache_block_group(root, cache); if (ret) @@ -206,22 +209,27 @@ again: last = max(search_start, cache->key.objectid); + 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 (data != BTRFS_BLOCK_GROUP_MIXED && start + num > cache->key.objectid + cache->key.offset) goto new_group; @@ -1420,6 +1428,7 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_block_group_cache *block_group; int full_scan = 0; int wrapped = 0; + int empty_cluster; u64 cached_start; WARN_ON(num_bytes < root->sectorsize); @@ -1431,11 +1440,15 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans, data = BTRFS_BLOCK_GROUP_MIXED; } - if (!data) + if (!data) { last_ptr = &root->fs_info->last_alloc; + empty_cluster = 128 * 1024; + } - if (data && btrfs_test_opt(root, SSD)) + if (data && btrfs_test_opt(root, SSD)) { last_ptr = &root->fs_info->last_data_alloc; + empty_cluster = 2 * 1024 * 1024; + } if (last_ptr) { if (*last_ptr) @@ -1443,8 +1456,9 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans, else { hint_byte = hint_byte & ~((u64)BTRFS_BLOCK_GROUP_SIZE - 1); - empty_size += 2 * 1024 * 1024; + empty_size += empty_cluster; } + search_start = max(search_start, hint_byte); } search_end = min(search_end, @@ -1476,7 +1490,7 @@ check_failed: if (last_ptr && *last_ptr && search_start != *last_ptr) { *last_ptr = 0; if (!empty_size) { - empty_size += 2 * 1024 * 1024; + empty_size += empty_cluster; total_needed += empty_size; } search_start = find_search_start(root, &block_group, diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 9262ab37a7cd..fb6400895ed6 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -255,7 +255,7 @@ static int merge_state(struct extent_io_tree *tree, state->start = other->start; other->tree = NULL; if (tree->last == other) - tree->last = NULL; + tree->last = state; rb_erase(&other->rb_node, &tree->state); free_extent_state(other); } @@ -268,7 +268,7 @@ static int merge_state(struct extent_io_tree *tree, other->start = state->start; state->tree = NULL; if (tree->last == state) - tree->last = NULL; + tree->last = other; rb_erase(&state->rb_node, &tree->state); free_extent_state(state); } @@ -397,8 +397,9 @@ static int clear_state_bit(struct extent_io_tree *tree, if (delete || state->state == 0) { if (state->tree) { clear_state_cb(tree, state, state->state); - if (tree->last == state) - tree->last = NULL; + if (tree->last == state) { + tree->last = extent_state_next(state); + } rb_erase(&state->rb_node, &tree->state); state->tree = NULL; free_extent_state(state); @@ -962,6 +963,35 @@ out: } EXPORT_SYMBOL(find_first_extent_bit); +struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree, + u64 start, int bits) +{ + struct rb_node *node; + struct extent_state *state; + + /* + * this search will find all the extents that end after + * our range starts. + */ + node = tree_search(tree, start); + if (!node || IS_ERR(node)) { + goto out; + } + + while(1) { + state = rb_entry(node, struct extent_state, rb_node); + if (state->end >= start && (state->state & bits)) { + return state; + } + node = rb_next(node); + if (!node) + break; + } +out: + return NULL; +} +EXPORT_SYMBOL(find_first_extent_bit_state); + u64 find_lock_delalloc_range(struct extent_io_tree *tree, u64 *start, u64 *end, u64 max_bytes) { diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 151fdada4dc4..fcc4bb078c24 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -81,6 +81,15 @@ struct extent_buffer { struct extent_map_tree; +static inline struct extent_state *extent_state_next(struct extent_state *state) +{ + struct rb_node *node; + node = rb_next(&state->rb_node); + if (!node) + return NULL; + return rb_entry(node, struct extent_state, rb_node); +} + typedef struct extent_map *(get_extent_t)(struct inode *inode, struct page *page, size_t page_offset, @@ -122,6 +131,8 @@ int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask); int find_first_extent_bit(struct extent_io_tree *tree, u64 start, u64 *start_ret, u64 *end_ret, int bits); +struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree, + u64 start, int bits); int extent_invalidatepage(struct extent_io_tree *tree, struct page *page, unsigned long offset); int extent_write_full_page(struct extent_io_tree *tree, struct page *page, -- 2.20.1