diff options
| author | Chris Mason <chris.mason@oracle.com> | 2012-03-03 07:40:03 -0500 |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2012-03-26 17:04:23 -0400 |
| commit | cfed81a04eb555f5606d1b6a54bdbabab0ee1ac3 (patch) | |
| tree | 2a763276869693b21c0e3a14f725f642c1f27fd3 /fs/btrfs/struct-funcs.c | |
| parent | 0b32f4bbb423f02acee6d43cd442f5f0775db7e0 (diff) | |
| download | linux-cfed81a04eb555f5606d1b6a54bdbabab0ee1ac3.tar.bz2 | |
Btrfs: add the ability to cache a pointer into the eb
This cuts down on the CPU time used by map_private_extent_buffer
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/struct-funcs.c')
| -rw-r--r-- | fs/btrfs/struct-funcs.c | 53 |
1 files changed, 46 insertions, 7 deletions
diff --git a/fs/btrfs/struct-funcs.c b/fs/btrfs/struct-funcs.c index bc1f6ad18442..c6ffa5812419 100644 --- a/fs/btrfs/struct-funcs.c +++ b/fs/btrfs/struct-funcs.c @@ -44,8 +44,9 @@ #define BTRFS_SETGET_FUNCS(name, type, member, bits) \ u##bits btrfs_##name(struct extent_buffer *eb, type *s); \ void btrfs_set_##name(struct extent_buffer *eb, type *s, u##bits val); \ -u##bits btrfs_##name(struct extent_buffer *eb, \ - type *s) \ +void btrfs_set_token_##name(struct extent_buffer *eb, type *s, u##bits val, struct btrfs_map_token *token); \ +u##bits btrfs_token_##name(struct extent_buffer *eb, \ + type *s, struct btrfs_map_token *token) \ { \ unsigned long part_offset = (unsigned long)s; \ unsigned long offset = part_offset + offsetof(type, member); \ @@ -54,9 +55,18 @@ u##bits btrfs_##name(struct extent_buffer *eb, \ char *kaddr; \ unsigned long map_start; \ unsigned long map_len; \ + unsigned long mem_len = sizeof(((type *)0)->member); \ u##bits res; \ + if (token && token->kaddr && token->offset <= offset && \ + token->eb == eb && \ + (token->offset + PAGE_CACHE_SIZE >= offset + mem_len)) { \ + kaddr = token->kaddr; \ + p = (type *)(kaddr + part_offset - token->offset); \ + res = le##bits##_to_cpu(p->member); \ + return res; \ + } \ err = map_private_extent_buffer(eb, offset, \ - sizeof(((type *)0)->member), \ + mem_len, \ &kaddr, &map_start, &map_len); \ if (err) { \ __le##bits leres; \ @@ -65,10 +75,15 @@ u##bits btrfs_##name(struct extent_buffer *eb, \ } \ p = (type *)(kaddr + part_offset - map_start); \ res = le##bits##_to_cpu(p->member); \ + if (token) { \ + token->kaddr = kaddr; \ + token->offset = map_start; \ + token->eb = eb; \ + } \ return res; \ } \ -void btrfs_set_##name(struct extent_buffer *eb, \ - type *s, u##bits val) \ +void btrfs_set_token_##name(struct extent_buffer *eb, \ + type *s, u##bits val, struct btrfs_map_token *token) \ { \ unsigned long part_offset = (unsigned long)s; \ unsigned long offset = part_offset + offsetof(type, member); \ @@ -77,8 +92,17 @@ void btrfs_set_##name(struct extent_buffer *eb, \ char *kaddr; \ unsigned long map_start; \ unsigned long map_len; \ + unsigned long mem_len = sizeof(((type *)0)->member); \ + if (token && token->kaddr && token->offset <= offset && \ + token->eb == eb && \ + (token->offset + PAGE_CACHE_SIZE >= offset + mem_len)) { \ + kaddr = token->kaddr; \ + p = (type *)(kaddr + part_offset - token->offset); \ + p->member = cpu_to_le##bits(val); \ + return; \ + } \ err = map_private_extent_buffer(eb, offset, \ - sizeof(((type *)0)->member), \ + mem_len, \ &kaddr, &map_start, &map_len); \ if (err) { \ __le##bits val2; \ @@ -88,7 +112,22 @@ void btrfs_set_##name(struct extent_buffer *eb, \ } \ p = (type *)(kaddr + part_offset - map_start); \ p->member = cpu_to_le##bits(val); \ -} + if (token) { \ + token->kaddr = kaddr; \ + token->offset = map_start; \ + token->eb = eb; \ + } \ +} \ +void btrfs_set_##name(struct extent_buffer *eb, \ + type *s, u##bits val) \ +{ \ + btrfs_set_token_##name(eb, s, val, NULL); \ +} \ +u##bits btrfs_##name(struct extent_buffer *eb, \ + type *s) \ +{ \ + return btrfs_token_##name(eb, s, NULL); \ +} \ #include "ctree.h" |