From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Brook Subject: Re: [PATCH v3 6/6] qemu_calculate_timeout: increase minimum timeout to 1h Date: Fri, 10 Feb 2012 09:52:25 +0000 Message-ID: <201202100952.26104.paul@codesourcery.com> References: <201202100026.40727.paul@codesourcery.com> <4F34CF5E.9080106@redhat.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-6" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4F34CF5E.9080106@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org To: Paolo Bonzini Cc: avi@redhat.com, xen-devel@lists.xensource.com, qemu-devel@nongnu.org, Stefano Stabellini List-Id: xen-devel@lists.xenproject.org > On 02/10/2012 01:26 AM, Paul Brook wrote: > > The reason we have this is because there are bits of code that rely on > > polling. IIRC slirp and the floppy DMA engine were the main culprits. > > qemu_calculate_timeout is an ugly hack to poll at least once a second, > > allowing the guest to make forward progress when we miss an event. > > At least the floppy DMA engine is fine with it, it uses idle bottom > halves (which are a hack and could be replaced by timers, but that's not > relevant now). I thought idle bottom halves were one of the things that made this timout necessary. How else are they going to get run? Paul