From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757046Ab0EUJkv (ORCPT ); Fri, 21 May 2010 05:40:51 -0400 Received: from 0122700014.0.fullrate.dk ([95.166.99.235]:60165 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754545Ab0EUJku (ORCPT ); Fri, 21 May 2010 05:40:50 -0400 Date: Fri, 21 May 2010 11:40:47 +0200 From: Jens Axboe To: Konstantin Khlebnikov Cc: linux-kernel@vger.kernel.org, Dmitry Monakhov Subject: Re: [PATCH 1/2] cfq-iosched: remove dead_key from cfq_io_context Message-ID: <20100521094047.GB11217@kernel.dk> References: <20100520192134.19366.88949.stgit@zurg> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100520192134.19366.88949.stgit@zurg> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 20 2010, Konstantin Khlebnikov wrote: > Remove ->dead_key field from cfq_io_context to shrink its size to 128 bytes. > (64 bytes for 32-bit hosts) > > Use lower bit in ->key as dead-mark, instead of moving key to separate field. > After this for dead cfq_io_context we got cic->key != cfqd automatically. > Thus, io_context's last-hit cache should work without changing. > > Now to check ->key for non-dead state compare it with cfqd, > instead of checking ->key for non-null value as it was before. > > Plus remove obsolete race protection in cfq_cic_lookup. > This race gone after v2.6.24-1728-g4ac845a This, and the second patch, look really good. How much testing have you done with it? -- Jens Axboe