On Wed, Nov 25, 2009 at 10:12:19PM +0800, Liuweni wrote:
> @@ -605,8 +605,8 @@ static unsigned long hash(struct super_block *sb, unsigned long hashval)
> {
> unsigned long tmp;
>
> - tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) /
> - L1_CACHE_BYTES;
> + tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) >>
> + L1_CACHE_SHIFT;
> tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> I_HASHBITS);
> return tmp & I_HASHMASK;
> }
Have you compared the compiler output before/after your change? I'd be
amazed if GCC isn't able to optimise division-by-a-constant-power-of-two
into shift-by-constant.
--
Matthew Wilcox Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
