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

@@ -750,7 +750,7 @@ static struct dentry *fat_fh_to_dentry(struct super_block *sb,
*/
result = d_obtain_alias(inode);
if (!IS_ERR(result))
result->d_op = sb->s_root->d_op;
d_set_d_op(result, sb->s_root->d_op);
return result;
}
@@ -800,7 +800,7 @@ static struct dentry *fat_get_parent(struct dentry *child)
parent = d_obtain_alias(inode);
if (!IS_ERR(parent))
parent->d_op = sb->s_root->d_op;
d_set_d_op(parent, sb->s_root->d_op);
out:
unlock_super(sb);