Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757568Ab2EIIZb (ORCPT ); Wed, 9 May 2012 04:25:31 -0400 Received: from 173-166-109-252-newengland.hfc.comcastbusiness.net ([173.166.109.252]:37157 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751030Ab2EIIZ3 (ORCPT ); Wed, 9 May 2012 04:25:29 -0400 Date: Wed, 9 May 2012 04:25:27 -0400 From: Christoph Hellwig To: Robert Hancock , linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org, Jeff Garzik , Zheng Liu Subject: Re: [RFC][PATCH] libata: enable SATA disk fua detection on default Message-ID: <20120509082527.GA10674@infradead.org> References: <1336447443-4685-1-git-send-email-wenqing.lz@taobao.com> <4FAA02DA.3000201@gmail.com> <20120509061956.GA12329@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120509061956.GA12329@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 761 Lines: 15 On Wed, May 09, 2012 at 02:19:56PM +0800, Zheng Liu wrote: > disable FUA detection for SATA disk. If FUA feature can be used, we > could disable io_barrier to improve the performance. Now one solution You can't run with -o nobarrier just because the driver/hardware support FUA. However the implementation of -o barrier (aka REQ_FUA) is a lot more efficient if it is implemented. If your workload has a high percentage of REQ_FUA requests it might be better to switch the disks to write through mode entirely. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/