@@ -5620,9 +5620,9 @@ void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
}
}
-void le_bitmap_set(u8 *map, unsigned int start, int len)
+void le_bitmap_set(unsigned long *map, unsigned int start, int len)
{
- u8 *p = map + BIT_BYTE(start);
+ u8 *p = ((u8 *)map) + BIT_BYTE(start);
const unsigned int size = start + len;
int bits_to_set = BITS_PER_BYTE - (start % BITS_PER_BYTE);
u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(start);
@@ -84,7 +84,7 @@ static inline int le_test_bit(int nr, const u8 *addr)
return 1U & (addr[BIT_BYTE(nr)] >> (nr & (BITS_PER_BYTE-1)));
}
-void le_bitmap_set(u8 *map, unsigned int start, int len);
+void le_bitmap_set(unsigned long *map, unsigned int start, int len);
struct extent_state;
struct btrfs_root;
@@ -138,9 +138,9 @@ static inline u32 free_space_bitmap_size(u64 size, u32 sectorsize)
return DIV_ROUND_UP((u32)div_u64(size, sectorsize), BITS_PER_BYTE);
}
-static u8 *alloc_bitmap(u32 bitmap_size)
+static unsigned long *alloc_bitmap(u32 bitmap_size)
{
- u8 *ret;
+ unsigned long *ret;
unsigned int nofs_flag;
/*
@@ -166,7 +166,8 @@ int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans,
struct btrfs_free_space_info *info;
struct btrfs_key key, found_key;
struct extent_buffer *leaf;
- u8 *bitmap, *bitmap_cursor;
+ unsigned long *bitmap;
+ char *bitmap_cursor;
u64 start, end;
u64 bitmap_range, i;
u32 bitmap_size, flags, expected_extent_count;
@@ -255,7 +256,7 @@ int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans,
goto out;
}
- bitmap_cursor = bitmap;
+ bitmap_cursor = (char *)bitmap;
bitmap_range = fs_info->sectorsize * BTRFS_FREE_SPACE_BITMAP_BITS;
i = start;
while (i < end) {
@@ -304,13 +305,10 @@ int convert_free_space_to_extents(struct btrfs_trans_handle *trans,
struct btrfs_free_space_info *info;
struct btrfs_key key, found_key;
struct extent_buffer *leaf;
- u8 *bitmap;
+ unsigned long *bitmap;
u64 start, end;
- /* Initialize to silence GCC. */
- u64 extent_start = 0;
- u64 offset;
u32 bitmap_size, flags, expected_extent_count;
- int prev_bit = 0, bit, bitnr;
+ unsigned long nrbits, start_bit, end_bit;
u32 extent_count = 0;
int done = 0, nr;
int ret;
@@ -348,7 +346,7 @@ int convert_free_space_to_extents(struct btrfs_trans_handle *trans,
break;
} else if (found_key.type == BTRFS_FREE_SPACE_BITMAP_KEY) {
unsigned long ptr;
- u8 *bitmap_cursor;
+ char *bitmap_cursor;
u32 bitmap_pos, data_size;
ASSERT(found_key.objectid >= start);
@@ -358,7 +356,7 @@ int convert_free_space_to_extents(struct btrfs_trans_handle *trans,
bitmap_pos = div_u64(found_key.objectid - start,
fs_info->sectorsize *
BITS_PER_BYTE);
- bitmap_cursor = bitmap + bitmap_pos;
+ bitmap_cursor = ((char *)bitmap) + bitmap_pos;
data_size = free_space_bitmap_size(found_key.offset,
fs_info->sectorsize);
@@ -392,32 +390,16 @@ int convert_free_space_to_extents(struct btrfs_trans_handle *trans,
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
- offset = start;
- bitnr = 0;
- while (offset < end) {
- bit = !!le_test_bit(bitnr, bitmap);
- if (prev_bit == 0 && bit == 1) {
- extent_start = offset;
- } else if (prev_bit == 1 && bit == 0) {
- key.objectid = extent_start;
- key.type = BTRFS_FREE_SPACE_EXTENT_KEY;
- key.offset = offset - extent_start;
-
- ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
- if (ret)
- goto out;
- btrfs_release_path(path);
+ nrbits = div_u64(block_group->key.offset, block_group->fs_info->sectorsize);
+ start_bit = find_next_bit_le(bitmap, nrbits, 0);
- extent_count++;
- }
- prev_bit = bit;
- offset += fs_info->sectorsize;
- bitnr++;
- }
- if (prev_bit == 1) {
- key.objectid = extent_start;
+ while (start_bit < nrbits) {
+ end_bit = find_next_zero_bit_le(bitmap, nrbits, start_bit);
+ ASSERT(start_bit < end_bit);
+
+ key.objectid = start + start_bit * block_group->fs_info->sectorsize;
key.type = BTRFS_FREE_SPACE_EXTENT_KEY;
- key.offset = end - extent_start;
+ key.offset = (end_bit - start_bit) * block_group->fs_info->sectorsize;
ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
if (ret)
@@ -425,6 +407,8 @@ int convert_free_space_to_extents(struct btrfs_trans_handle *trans,
btrfs_release_path(path);
extent_count++;
+
+ start_bit = find_next_bit_le(bitmap, nrbits, end_bit);
}
if (extent_count != expected_extent_count) {
Presently, convert_free_space_to_extents() does a linear scan of the bitmap. We can speed this up with find_next_{bit,zero_bit}_le(). This patch replaces the linear scan with find_next_{bit,zero_bit}_le(). Testing shows a 20-33% decrease in execution time for convert_free_space_to_extents(). Suggested-by: Omar Sandoval <osandov@osandov.com> Signed-off-by: Howard McLauchlan <hmclauchlan@fb.com> --- Since we change bitmap to be unsigned long, we have to do some casting for the bitmap cursor. In le_bitmap_set() it makes sense to use u8, as we are doing bit operations. Everywhere else, we're just using it for pointer arithmetic and not directly accessing it, so char seems more appropriate. Howard fs/btrfs/extent_io.c | 4 +-- fs/btrfs/extent_io.h | 2 +- fs/btrfs/free-space-tree.c | 54 ++++++++++++++------------------------ 3 files changed, 22 insertions(+), 38 deletions(-)