From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [patch v3 1/3] block: add a non-queueable flush flag Date: Wed, 04 May 2011 22:17:39 -0400 Message-ID: <4DC208C3.7070902@pobox.com> References: <20110505015932.306763905@sli10-conroe.sh.intel.com> <20110505020417.586891398@sli10-conroe.sh.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-gw0-f46.google.com ([74.125.83.46]:56910 "EHLO mail-gw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750794Ab1EECRm (ORCPT ); Wed, 4 May 2011 22:17:42 -0400 In-Reply-To: <20110505020417.586891398@sli10-conroe.sh.intel.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: shaohua.li@intel.com Cc: linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, jaxboe@fusionio.com, htejun@gmail.com, hch@infradead.org, djwong@us.ibm.com, sshtylyov@mvista.com On 05/04/2011 09:59 PM, shaohua.li@intel.com wrote: > flush request isn't queueable in some drives. Add a flag to let driver > notify block layer about this. We can optimize flush performance with the > knowledge. > > Signed-off-by: Shaohua Li > --- > block/blk-settings.c | 6 ++++++ > include/linux/blkdev.h | 7 +++++++ > 2 files changed, 13 insertions(+) hmmm. This assumes that flush on new hardware, by default, is queueable. I think the sense should be reversed: don't enable the optimization, unless we know the optimization works. That seems safer than always enabling the optimization, unless we know it does not work. That is not a fail-safe mode of operation. Jeff