Commit 3685f791 authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: CPU usage optimizations in push and the extent_map code 



Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 59d169e2

fs/btrfs/ctree.c

+24 −20
Original line number Diff line number Diff line
@@ -1588,6 +1588,11 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root 
	if (!path->nodes[1])

		return 1;



	right_nritems = btrfs_header_nritems(right);

	if (right_nritems == 0) {

		return 1;

	}



	left = read_tree_block(root, btrfs_node_blockptr(path->nodes[1],

			       slot - 1), root->leafsize);

	free_space = btrfs_leaf_free_space(root, left);
@@ -1604,18 +1609,13 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root 
		free_extent_buffer(left);

		return 1;

	}



	free_space = btrfs_leaf_free_space(root, left);

	if (free_space < data_size + sizeof(struct btrfs_item)) {

		free_extent_buffer(left);

		return 1;

	}



	right_nritems = btrfs_header_nritems(right);

	if (right_nritems == 0) {

		free_extent_buffer(left);

		return 1;

	}



	for (i = 0; i < right_nritems - 1; i++) {

		item = btrfs_item_nr(right, i);

		if (!right->map_token) {
@@ -1772,12 +1772,13 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root 
	struct btrfs_disk_key disk_key;



	/* first try to make some room by pushing left and right */

	wret = push_leaf_left(trans, root, path, data_size);

	if (ins_key->type != BTRFS_DIR_ITEM_KEY) {

		wret = push_leaf_right(trans, root, path, data_size);

		if (wret < 0) {

			return wret;

		}

		if (wret) {

		wret = push_leaf_right(trans, root, path, data_size);

			wret = push_leaf_left(trans, root, path, data_size);

			if (wret < 0)

				return wret;

		}
@@ -1788,6 +1789,9 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root 
		    sizeof(struct btrfs_item) + data_size) {

			return 0;

		}

	} else {

		l = path->nodes[0];

	}



	if (!path->nodes[1]) {

		ret = insert_new_root(trans, root, path, 1);
@@ -2388,13 +2392,13 @@ int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, 
			slot = path->slots[1];

			extent_buffer_get(leaf);



			wret = push_leaf_left(trans, root, path, 1);

			wret = push_leaf_right(trans, root, path, 1);

			if (wret < 0 && wret != -ENOSPC)

				ret = wret;



			if (path->nodes[0] == leaf &&

			    btrfs_header_nritems(leaf)) {

				wret = push_leaf_right(trans, root, path, 1);

				wret = push_leaf_left(trans, root, path, 1);

				if (wret < 0 && wret != -ENOSPC)

					ret = wret;

			}

fs/btrfs/extent_map.c

+15 −30
Original line number Diff line number Diff line
@@ -1986,12 +1986,15 @@ static inline struct page *extent_buffer_page(struct extent_buffer *eb, 
					      unsigned long i)

{

	struct page *p;

	struct address_space *mapping;



	if (i == 0)

		return eb->first_page;

	i += eb->start >> PAGE_CACHE_SHIFT;

	p = find_get_page(eb->first_page->mapping, i);

	page_cache_release(p);

	mapping = eb->first_page->mapping;

	read_lock_irq(&mapping->tree_lock);

	p = radix_tree_lookup(&mapping->page_tree, i);

	read_unlock_irq(&mapping->tree_lock);

	return p;

}
@@ -2365,9 +2368,7 @@ void read_extent_buffer(struct extent_buffer *eb, void *dstv, 
	WARN_ON(start > eb->len);

	WARN_ON(start + len > eb->start + eb->len);



	offset = start & ((unsigned long)PAGE_CACHE_SIZE - 1);

	if (i == 0)

		offset += start_offset;

	offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);



	while(len > 0) {

		page = extent_buffer_page(eb, i);
@@ -2475,9 +2476,7 @@ int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv, 
	WARN_ON(start > eb->len);

	WARN_ON(start + len > eb->start + eb->len);



	offset = start & ((unsigned long)PAGE_CACHE_SIZE - 1);

	if (i == 0)

		offset += start_offset;

	offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);



	while(len > 0) {

		page = extent_buffer_page(eb, i);
@@ -2514,9 +2513,7 @@ void write_extent_buffer(struct extent_buffer *eb, const void *srcv, 
	WARN_ON(start > eb->len);

	WARN_ON(start + len > eb->start + eb->len);



	offset = start & ((unsigned long)PAGE_CACHE_SIZE - 1);

	if (i == 0)

		offset += start_offset;

	offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);



	while(len > 0) {

		page = extent_buffer_page(eb, i);
@@ -2548,9 +2545,7 @@ void memset_extent_buffer(struct extent_buffer *eb, char c, 
	WARN_ON(start > eb->len);

	WARN_ON(start + len > eb->start + eb->len);



	offset = start & ((unsigned long)PAGE_CACHE_SIZE - 1);

	if (i == 0)

		offset += start_offset;

	offset = (start_offset + start) & ((unsigned long)PAGE_CACHE_SIZE - 1);



	while(len > 0) {

		page = extent_buffer_page(eb, i);
@@ -2582,9 +2577,8 @@ void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src, 


	WARN_ON(src->len != dst_len);



	offset = dst_offset & ((unsigned long)PAGE_CACHE_SIZE - 1);

	if (i == 0)

		offset += start_offset;

	offset = (start_offset + dst_offset) &

		((unsigned long)PAGE_CACHE_SIZE - 1);



	while(len > 0) {

		page = extent_buffer_page(dst, i);
@@ -2664,19 +2658,14 @@ void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 
	}



	while(len > 0) {

		dst_off_in_page = dst_offset &

		dst_off_in_page = (start_offset + dst_offset) &

			((unsigned long)PAGE_CACHE_SIZE - 1);

		src_off_in_page = src_offset &

		src_off_in_page = (start_offset + src_offset) &

			((unsigned long)PAGE_CACHE_SIZE - 1);



		dst_i = (start_offset + dst_offset) >> PAGE_CACHE_SHIFT;

		src_i = (start_offset + src_offset) >> PAGE_CACHE_SHIFT;



		if (src_i == 0)

			src_off_in_page += start_offset;

		if (dst_i == 0)

			dst_off_in_page += start_offset;



		cur = min(len, (unsigned long)(PAGE_CACHE_SIZE -

					       src_off_in_page));

		cur = min_t(unsigned long, cur,
@@ -2723,14 +2712,10 @@ void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 
		dst_i = (start_offset + dst_end) >> PAGE_CACHE_SHIFT;

		src_i = (start_offset + src_end) >> PAGE_CACHE_SHIFT;



		dst_off_in_page = dst_end &

		dst_off_in_page = (start_offset + dst_end) &

			((unsigned long)PAGE_CACHE_SIZE - 1);

		src_off_in_page = src_end &

		src_off_in_page = (start_offset + src_end) &

			((unsigned long)PAGE_CACHE_SIZE - 1);

		if (src_i == 0)

			src_off_in_page += start_offset;

		if (dst_i == 0)

			dst_off_in_page += start_offset;



		cur = min_t(unsigned long, len, src_off_in_page + 1);

		cur = min(cur, dst_off_in_page + 1);