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Btrfs: CPU usage optimizations in push and the extent_map code
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Signed-off-by: Chris Mason <chris.mason@oracle.com>
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Chris Mason committed Sep 25, 2008
1 parent 59d169e commit 3685f79
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Showing 2 changed files with 39 additions and 50 deletions.
44 changes: 24 additions & 20 deletions fs/btrfs/ctree.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand All @@ -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) {
Expand Down Expand Up @@ -1772,21 +1772,25 @@ 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 (wret < 0) {
return wret;
}
if (wret) {
if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
wret = push_leaf_right(trans, root, path, data_size);
if (wret < 0)
if (wret < 0) {
return wret;
}
l = path->nodes[0];
}
if (wret) {
wret = push_leaf_left(trans, root, path, data_size);
if (wret < 0)
return wret;
}
l = path->nodes[0];

/* did the pushes work? */
if (btrfs_leaf_free_space(root, l) >=
sizeof(struct btrfs_item) + data_size) {
return 0;
/* did the pushes work? */
if (btrfs_leaf_free_space(root, l) >=
sizeof(struct btrfs_item) + data_size) {
return 0;
}
} else {
l = path->nodes[0];
}

if (!path->nodes[1]) {
Expand Down Expand Up @@ -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;
}
Expand Down
45 changes: 15 additions & 30 deletions fs/btrfs/extent_map.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
}

Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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,
Expand Down Expand Up @@ -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);
Expand Down

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