diff options
| author | Hanna V. Linder <hannal@us.ibm.com> | 2002-04-24 01:24:02 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@penguin.transmeta.com> | 2002-04-24 01:24:02 -0700 |
| commit | 898683e9fabbbc9c9e837551f996423853fb26ba (patch) | |
| tree | 3ec2bab3ac1e23ff998f849d1f46955b6cee1763 /include/linux/fs.h | |
| parent | fe7885a4a5fdca56365343251b3007b67b77da86 (diff) | |
[PATCH] FastWalk Dcache
Reduce cacheline bouncing when a dentry is in the cache.
Specifically, the d_count reference counter is not incremented and
decremented for every dentry in a path during path walking if the dentry
is in the dcache. Execcisve atomic inc/dec's are expensive on SMP
systems due to the cachline bouncing.
Diffstat (limited to 'include/linux/fs.h')
| -rw-r--r-- | include/linux/fs.h | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index 72a40b3bbda4..a97a764dcc53 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1386,12 +1386,15 @@ extern ino_t find_inode_number(struct dentry *, struct qstr *); * - require a directory * - ending slashes ok even for nonexistent files * - internal "there are more path compnents" flag + * - locked when lookup done with dcache_lock held */ #define LOOKUP_FOLLOW (1) #define LOOKUP_DIRECTORY (2) #define LOOKUP_CONTINUE (4) #define LOOKUP_PARENT (16) #define LOOKUP_NOALT (32) +#define LOOKUP_LOCKED (64) + /* * Type of the last component on LOOKUP_PARENT */ @@ -1421,14 +1424,8 @@ extern loff_t default_llseek(struct file *file, loff_t offset, int origin); extern int FASTCALL(__user_walk(const char *, unsigned, struct nameidata *)); extern int FASTCALL(path_init(const char *, unsigned, struct nameidata *)); extern int FASTCALL(path_walk(const char *, struct nameidata *)); +extern int FASTCALL(path_lookup(const char *, unsigned, struct nameidata *)); extern int FASTCALL(link_path_walk(const char *, struct nameidata *)); -static inline int path_lookup(const char *path, unsigned flags, struct nameidata *nd) -{ - int error = 0; - if (path_init(path, flags, nd)) - error = path_walk(path, nd); - return error; -} extern void path_release(struct nameidata *); extern int follow_down(struct vfsmount **, struct dentry **); extern int follow_up(struct vfsmount **, struct dentry **); |