fs/dcache.c: Save one 32-bit multiply in dcache lookup
Noe that we're mixing in the parent pointer earlier, we
don't need to use hash_32() to mix its bits. Instead, we can
just take the msbits of the hash value directly.
For those applications which use the partial_name_hash(),
move the multiply to end_name_hash.
Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/dcache.c b/fs/dcache.c
index 9522b8b..03f1a33 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -106,7 +106,7 @@
static inline struct hlist_bl_head *d_hash(unsigned int hash)
{
- return dentry_hashtable + hash_32(hash, d_hash_shift);
+ return dentry_hashtable + (hash >> (32 - d_hash_shift));
}
#define IN_LOOKUP_SHIFT 10