From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamie Lokier Subject: Re: [Qemu-devel] Re: [PATCH 1/3] Refactor AIO interface to allow other AIO implementations Date: Fri, 18 Apr 2008 17:22:13 +0100 Message-ID: <20080418162212.GB31520@shareable.org> References: <1208460412-27567-1-git-send-email-aliguori@us.ibm.com> <20080417193807.GB11916@redhat.com> <4807A7EC.6040408@us.ibm.com> <20080417200024.GC11916@redhat.com> <20080418124319.GC25089@shareable.org> <4808BCF3.3060200@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel@lists.sourceforge.net, Marcelo Tosatti To: qemu-devel@nongnu.org Return-path: Content-Disposition: inline In-Reply-To: <4808BCF3.3060200@us.ibm.com> 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 Anthony Liguori wrote: > >I'm of the view that '-aio auto' would be a really good option - and > >when it's proven itself, it should be the default. It could work on > >all QEMU hosts: it would pick synchronous IO when there is nothing else. > > Right now, not specifying the -aio option is equivalent to your proposed > -aio auto. > > I guess I should include an info aio to let the user know what type of > aio they are using. We can add selection criteria later but > semantically, not specifying an explicit -aio option allows QEMU to > choose whichever one it thinks is best. Great. I guess the next step is to add selection criteria, otherwise a million Wikis will tell everyone to use '-aio linux' :-) Do you know what the selection criteria should be - or is there a document/paper somewhere which says (ideally from benchmarks)? I'm interested for an unrelated project using AIO - so I'm willing to help get this right to some extent. -- Jamie ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1JmtM2-0000DQ-85 for qemu-devel@nongnu.org; Fri, 18 Apr 2008 12:22:26 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1JmtLy-0000CZ-Kt for qemu-devel@nongnu.org; Fri, 18 Apr 2008 12:22:25 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1JmtLy-0000CW-DY for qemu-devel@nongnu.org; Fri, 18 Apr 2008 12:22:22 -0400 Received: from mail2.shareable.org ([80.68.89.115]) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1JmtLx-0003Iv-Pn for qemu-devel@nongnu.org; Fri, 18 Apr 2008 12:22:22 -0400 Date: Fri, 18 Apr 2008 17:22:13 +0100 From: Jamie Lokier Subject: Re: [Qemu-devel] Re: [kvm-devel] [PATCH 1/3] Refactor AIO interface to allow other AIO implementations Message-ID: <20080418162212.GB31520@shareable.org> References: <1208460412-27567-1-git-send-email-aliguori@us.ibm.com> <20080417193807.GB11916@redhat.com> <4807A7EC.6040408@us.ibm.com> <20080417200024.GC11916@redhat.com> <20080418124319.GC25089@shareable.org> <4808BCF3.3060200@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4808BCF3.3060200@us.ibm.com> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kvm-devel@lists.sourceforge.net, Anthony Liguori , Marcelo Tosatti Anthony Liguori wrote: > >I'm of the view that '-aio auto' would be a really good option - and > >when it's proven itself, it should be the default. It could work on > >all QEMU hosts: it would pick synchronous IO when there is nothing else. > > Right now, not specifying the -aio option is equivalent to your proposed > -aio auto. > > I guess I should include an info aio to let the user know what type of > aio they are using. We can add selection criteria later but > semantically, not specifying an explicit -aio option allows QEMU to > choose whichever one it thinks is best. Great. I guess the next step is to add selection criteria, otherwise a million Wikis will tell everyone to use '-aio linux' :-) Do you know what the selection criteria should be - or is there a document/paper somewhere which says (ideally from benchmarks)? I'm interested for an unrelated project using AIO - so I'm willing to help get this right to some extent. -- Jamie