From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751411AbWAKTU6 (ORCPT ); Wed, 11 Jan 2006 14:20:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751718AbWAKTU6 (ORCPT ); Wed, 11 Jan 2006 14:20:58 -0500 Received: from web34113.mail.mud.yahoo.com ([66.163.178.111]:22350 "HELO web34113.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S1751411AbWAKTU6 (ORCPT ); Wed, 11 Jan 2006 14:20:58 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:Received:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=q/eFWMt2ylblEL2F0VAyhAIHJSGl2UP6VMB58thwqQwvsUXQJFDgr6xnK4t3cDY9lfuYMRSiWcxfJIk/Q1FirUFJBEV2kEmIwsxjORQWmemGm8AujnhceVvgvMY+hb5sx7+Y2rmqsF8az0GSmreRdvlNo6roqK/nnGhcW7BcLrQ= ; Message-ID: <20060111192056.67364.qmail@web34113.mail.mud.yahoo.com> Date: Wed, 11 Jan 2006 11:20:56 -0800 (PST) From: Kenny Simpson Subject: Re: Is user-space AIO dead? To: David Lloyd Cc: linux kernel In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --- David Lloyd wrote: > On Wed, 11 Jan 2006, Kenny Simpson wrote: > > > --- David Lloyd wrote: > >> Wouldn't nonblocking I/O on regular files be nice? > > > > Yes it could be. As I understand it, regular file writes (not O_DIRECT) > > are only to the page cache and only block when there is memory pressure > > (so it is more of a throttle). > > If you were however using O_DIRECT or O_SYNC, you would then have a > mechanism to know when your writes have made it to disk, which might be > useful for transactional systems. Right, but I'm not sure O_DIRECT implies stable storage, only data sent out to the device, not held up in the page cache (I could be wrong). AIO is implemented for O_DIRECT according to the paper, but they observed it not having benefit. AIO being implemented to O_SYNC would be nice for my use, as it would also eliminate the extra alignment restrictions brought on by O_DIRECT. -Kenny __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com