Re: dentry cache order 7 is broken

[Mitchell Blank Jr]

David S. Miller wrote:
> -	hash = hash ^ (hash >> D_HASHBITS) ^ (hash >> D_HASHBITS*2);
> +	hash = hash ^ (hash >> D_HASHBITS) ^
> +		(hash >> (D_HASHBITS+(D_HASHBITS/2)));

Two comments:
  1. The inode-cache has the exact same problem, but it'll require a lot
     of RAM to run into it.  The buffer and page caches don't have the
     same problem.
  2. Given that D_HASHBITS is not a constant I wonder if there isn't
     a more efficient hash to be found.  But I guess I'll leave that
     to the hashing experts.

-Mitch