From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Brook Subject: Re: [Qemu-devel] [PATCH] QEMU: fsync AIO writes on flush request Date: Sat, 29 Mar 2008 02:02:53 +0000 Message-ID: <200803290202.54431.paul@codesourcery.com> References: <20080328150517.GA18077@dmt> <20080328181311.GA19547@dmt> <20080329011751.GB30219@shareable.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel , Jamie Lokier To: qemu-devel@nongnu.org Return-path: In-Reply-To: <20080329011751.GB30219@shareable.org> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces@lists.sourceforge.net Errors-To: kvm-devel-bounces@lists.sourceforge.net List-Id: kvm.vger.kernel.org > That'll depend on what kind of device is emulated. Does the SCSI > emulation handle multiple in-flight commands with any guarantee on > order? SCSI definitely allows (and we emulate) multiple in flight commands. I can't find any requirement that writes must complete before a subsequent SYNCHRONISE_CACHE. However I don't claim to know the spec that well, and it's probably not a bad idea have them complete anyway. Preferably this would be a completely asynchronous operation. i.e. the sync command returns immediately, but only completes when all preceding writes have completed and been flushed to disk. Paul ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace