linux-kernel - Re: [patch 12/14] fs: dcache per-bucket dcache hash locking

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <878wmnnr73.fsf@basil.nowhere.org>
Date:	Mon, 30 Mar 2009 14:14:08 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	npiggin@...e.de
Cc:	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [patch 12/14] fs: dcache per-bucket dcache hash locking

npiggin@...e.de writes:

> We can turn the dcache hash locking from a global dcache_hash_lock into
> per-bucket locking.

Per bucket locking is typically a bad idea because you get far too
many locks and you increase cache footprint with all of them. It's
typically better to use a second much smaller hash table that only has
locks (by just shifting the hash value down some more) 
Just need to be careful to avoid too much false sharing.

-Andi

-- 
ak@...ux.intel.com -- Speaking for myself only.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/