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>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 74c03fb..8af24da 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2333,6 +2333,7 @@
{
struct extent_buffer *left = path->nodes[0];
struct extent_buffer *upper = path->nodes[1];
+ struct btrfs_map_token token;
struct btrfs_disk_key disk_key;
int slot;
u32 i;
@@ -2344,6 +2345,8 @@
u32 data_end;
u32 this_item_size;
+ btrfs_init_map_token(&token);
+
if (empty)
nr = 0;
else
@@ -2421,8 +2424,8 @@
push_space = BTRFS_LEAF_DATA_SIZE(root);
for (i = 0; i < right_nritems; i++) {
item = btrfs_item_nr(right, i);
- push_space -= btrfs_item_size(right, item);
- btrfs_set_item_offset(right, item, push_space);
+ push_space -= btrfs_token_item_size(right, item, &token);
+ btrfs_set_token_item_offset(right, item, push_space, &token);
}
left_nritems -= push_items;
@@ -2553,6 +2556,9 @@
int wret;
u32 this_item_size;
u32 old_left_item_size;
+ struct btrfs_map_token token;
+
+ btrfs_init_map_token(&token);
if (empty)
nr = min(right_nritems, max_slot);
@@ -2613,9 +2619,10 @@
item = btrfs_item_nr(left, i);
- ioff = btrfs_item_offset(left, item);
- btrfs_set_item_offset(left, item,
- ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
+ ioff = btrfs_token_item_offset(left, item, &token);
+ btrfs_set_token_item_offset(left, item,
+ ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size),
+ &token);
}
btrfs_set_header_nritems(left, old_left_nritems + push_items);
@@ -2645,8 +2652,9 @@
for (i = 0; i < right_nritems; i++) {
item = btrfs_item_nr(right, i);
- push_space = push_space - btrfs_item_size(right, item);
- btrfs_set_item_offset(right, item, push_space);
+ push_space = push_space - btrfs_token_item_size(right,
+ item, &token);
+ btrfs_set_token_item_offset(right, item, push_space, &token);
}
btrfs_mark_buffer_dirty(left);
@@ -2767,6 +2775,9 @@
int ret = 0;
int wret;
struct btrfs_disk_key disk_key;
+ struct btrfs_map_token token;
+
+ btrfs_init_map_token(&token);
nritems = nritems - mid;
btrfs_set_header_nritems(right, nritems);
@@ -2788,8 +2799,9 @@
struct btrfs_item *item = btrfs_item_nr(right, i);
u32 ioff;
- ioff = btrfs_item_offset(right, item);
- btrfs_set_item_offset(right, item, ioff + rt_data_off);
+ ioff = btrfs_token_item_offset(right, item, &token);
+ btrfs_set_token_item_offset(right, item,
+ ioff + rt_data_off, &token);
}
btrfs_set_header_nritems(l, mid);
@@ -3284,6 +3296,9 @@
unsigned int old_size;
unsigned int size_diff;
int i;
+ struct btrfs_map_token token;
+
+ btrfs_init_map_token(&token);
leaf = path->nodes[0];
slot = path->slots[0];
@@ -3310,8 +3325,9 @@
u32 ioff;
item = btrfs_item_nr(leaf, i);
- ioff = btrfs_item_offset(leaf, item);
- btrfs_set_item_offset(leaf, item, ioff + size_diff);
+ ioff = btrfs_token_item_offset(leaf, item, &token);
+ btrfs_set_token_item_offset(leaf, item,
+ ioff + size_diff, &token);
}
/* shift the data */
@@ -3381,6 +3397,9 @@
unsigned int old_data;
unsigned int old_size;
int i;
+ struct btrfs_map_token token;
+
+ btrfs_init_map_token(&token);
leaf = path->nodes[0];
@@ -3410,8 +3429,9 @@
u32 ioff;
item = btrfs_item_nr(leaf, i);
- ioff = btrfs_item_offset(leaf, item);
- btrfs_set_item_offset(leaf, item, ioff - data_size);
+ ioff = btrfs_token_item_offset(leaf, item, &token);
+ btrfs_set_token_item_offset(leaf, item,
+ ioff - data_size, &token);
}
/* shift the data */
@@ -3454,6 +3474,9 @@
unsigned int data_end;
struct btrfs_disk_key disk_key;
struct btrfs_key found_key;
+ struct btrfs_map_token token;
+
+ btrfs_init_map_token(&token);
for (i = 0; i < nr; i++) {
if (total_size + data_size[i] + sizeof(struct btrfs_item) >
@@ -3519,8 +3542,9 @@
u32 ioff;
item = btrfs_item_nr(leaf, i);
- ioff = btrfs_item_offset(leaf, item);
- btrfs_set_item_offset(leaf, item, ioff - total_data);
+ ioff = btrfs_token_item_offset(leaf, item, &token);
+ btrfs_set_token_item_offset(leaf, item,
+ ioff - total_data, &token);
}
/* shift the items */
memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
@@ -3547,9 +3571,10 @@
btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
btrfs_set_item_key(leaf, &disk_key, slot + i);
item = btrfs_item_nr(leaf, slot + i);
- btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
+ btrfs_set_token_item_offset(leaf, item,
+ data_end - data_size[i], &token);
data_end -= data_size[i];
- btrfs_set_item_size(leaf, item, data_size[i]);
+ btrfs_set_token_item_size(leaf, item, data_size[i], &token);
}
btrfs_set_header_nritems(leaf, nritems + nr);
btrfs_mark_buffer_dirty(leaf);
@@ -3588,6 +3613,9 @@
int ret;
struct extent_buffer *leaf;
int slot;
+ struct btrfs_map_token token;
+
+ btrfs_init_map_token(&token);
leaf = path->nodes[0];
slot = path->slots[0];
@@ -3619,8 +3647,9 @@
u32 ioff;
item = btrfs_item_nr(leaf, i);
- ioff = btrfs_item_offset(leaf, item);
- btrfs_set_item_offset(leaf, item, ioff - total_data);
+ ioff = btrfs_token_item_offset(leaf, item, &token);
+ btrfs_set_token_item_offset(leaf, item,
+ ioff - total_data, &token);
}
/* shift the items */
memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
@@ -3639,9 +3668,10 @@
btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
btrfs_set_item_key(leaf, &disk_key, slot + i);
item = btrfs_item_nr(leaf, slot + i);
- btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
+ btrfs_set_token_item_offset(leaf, item,
+ data_end - data_size[i], &token);
data_end -= data_size[i];
- btrfs_set_item_size(leaf, item, data_size[i]);
+ btrfs_set_token_item_size(leaf, item, data_size[i], &token);
}
btrfs_set_header_nritems(leaf, nritems + nr);
@@ -3814,6 +3844,9 @@
int wret;
int i;
u32 nritems;
+ struct btrfs_map_token token;
+
+ btrfs_init_map_token(&token);
leaf = path->nodes[0];
last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
@@ -3835,8 +3868,9 @@
u32 ioff;
item = btrfs_item_nr(leaf, i);
- ioff = btrfs_item_offset(leaf, item);
- btrfs_set_item_offset(leaf, item, ioff + dsize);
+ ioff = btrfs_token_item_offset(leaf, item, &token);
+ btrfs_set_token_item_offset(leaf, item,
+ ioff + dsize, &token);
}
memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 85ab1c5..c2e17cd 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1546,6 +1546,17 @@
#define BTRFS_INODE_ROOT_ITEM_INIT (1 << 31)
+struct btrfs_map_token {
+ struct extent_buffer *eb;
+ char *kaddr;
+ unsigned long offset;
+};
+
+static inline void btrfs_init_map_token (struct btrfs_map_token *token)
+{
+ memset(token, 0, sizeof(*token));
+}
+
/* some macros to generate set/get funcs for the struct fields. This
* assumes there is a lefoo_to_cpu for every type, so lets make a simple
* one for u8:
@@ -1569,6 +1580,8 @@
#ifndef BTRFS_SETGET_FUNCS
#define BTRFS_SETGET_FUNCS(name, type, member, bits) \
u##bits btrfs_##name(struct extent_buffer *eb, type *s); \
+u##bits btrfs_token_##name(struct extent_buffer *eb, type *s, struct btrfs_map_token *token); \
+void btrfs_set_token_##name(struct extent_buffer *eb, type *s, u##bits val, struct btrfs_map_token *token);\
void btrfs_set_##name(struct extent_buffer *eb, type *s, u##bits val);
#endif
diff --git a/fs/btrfs/struct-funcs.c b/fs/btrfs/struct-funcs.c
index bc1f6ad..c6ffa58 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 @@
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 @@
} \
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 @@
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 @@
} \
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"