From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:36658) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RvoLr-0005QY-3c for qemu-devel@nongnu.org; Fri, 10 Feb 2012 06:09:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RvoLl-0000Ft-Fn for qemu-devel@nongnu.org; Fri, 10 Feb 2012 06:09:15 -0500 Received: from relay1.mentorg.com ([192.94.38.131]:62423) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RvoLl-0000EX-7U for qemu-devel@nongnu.org; Fri, 10 Feb 2012 06:09:09 -0500 From: Paul Brook Date: Fri, 10 Feb 2012 11:09:02 +0000 References: <201202100952.26104.paul@codesourcery.com> <4F34F567.3040309@redhat.com> In-Reply-To: <4F34F567.3040309@redhat.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-6" Content-Transfer-Encoding: 7bit Message-Id: <201202101109.03374.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 > >> > 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? > > The timeout is reduced to 10 ms when an idle bottom half is scheduled. > See qemu_bh_update_timeout in async.c. Ah, I see. Idle BH are indeed a nasty hack that should be removed, but not directly relevant to this 1s timeout. I don't think this changes my overall conlusion: Either we need this timeout to poll below the user-thinks-qemu-died threshold, or we should be blocking indefinitely. Paul