fs: dcache reduce branches in lookup path

Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.

Patched with:

git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
This commit is contained in:
Nick Piggin
2011-01-07 17:49:55 +11:00
parent 5f57cbcc02
commit fb045adb99
63 changed files with 174 additions and 137 deletions

View File

@ -701,7 +701,7 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
/* instantiate and hash dentry */
ret = d_find_alias(inode);
if (!ret) {
dentry->d_op = &sysfs_dentry_ops;
d_set_d_op(dentry, &sysfs_dentry_ops);
dentry->d_fsdata = sysfs_get(sd);
d_add(dentry, inode);
} else {