From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:40010) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Rvn9e-0002mr-CM for qemu-devel@nongnu.org; Fri, 10 Feb 2012 04:52:39 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Rvn9d-0001MU-H8 for qemu-devel@nongnu.org; Fri, 10 Feb 2012 04:52:34 -0500 Received: from relay1.mentorg.com ([192.94.38.131]:55394) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Rvn9d-0001MO-Bd for qemu-devel@nongnu.org; Fri, 10 Feb 2012 04:52:33 -0500 From: Paul Brook Date: Fri, 10 Feb 2012 09:52:25 +0000 References: <201202100026.40727.paul@codesourcery.com> <4F34CF5E.9080106@redhat.com> In-Reply-To: <4F34CF5E.9080106@redhat.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-6" Content-Transfer-Encoding: 7bit Message-Id: <201202100952.26104.paul@codesourcery.com> Subject: Re: [Qemu-devel] [PATCH v3 6/6] qemu_calculate_timeout: increase minimum timeout to 1h List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: avi@redhat.com, xen-devel@lists.xensource.com, qemu-devel@nongnu.org, Stefano Stabellini > 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