Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754695Ab0AURxW (ORCPT ); Thu, 21 Jan 2010 12:53:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754579Ab0AURxV (ORCPT ); Thu, 21 Jan 2010 12:53:21 -0500 Received: from mx1.redhat.com ([209.132.183.28]:14333 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754546Ab0AURxU (ORCPT ); Thu, 21 Jan 2010 12:53:20 -0500 Date: Thu, 21 Jan 2010 19:50:15 +0200 From: "Michael S. Tsirkin" To: Davide Libenzi Cc: Avi Kivity , mtosatti@redhat.com, kvm@vger.kernel.org, Linux Kernel Mailing List Subject: Re: [PATCHv2 1/3] eventfd: allow atomic read and waitqueue remove Message-ID: <20100121175014.GI16707@redhat.com> References: <20100121162648.GA16458@redhat.com> <4B588B29.2050100@redhat.com> <20100121172336.GA16707@redhat.com> <4B588FCE.7030803@redhat.com> <20100121173259.GC16707@redhat.com> <4B58933C.4090209@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 717 Lines: 26 On Thu, Jan 21, 2010 at 09:50:34AM -0800, Davide Libenzi wrote: > On Thu, 21 Jan 2010, Avi Kivity wrote: > > > On 01/21/2010 07:32 PM, Michael S. Tsirkin wrote: > > > > > > > Can't you read from the file? > > > > > > > IMO no, the read could block. > > > > > > > But you're in process context. An eventfd never blocks. > > Can you control the eventfd flags? Because if yes, O_NONBLOCK will never > block. > Userspace can but kvm can't. > > - Davide > -- 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/