From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762115AbXGDO6i (ORCPT ); Wed, 4 Jul 2007 10:58:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757712AbXGDO6c (ORCPT ); Wed, 4 Jul 2007 10:58:32 -0400 Received: from cavan.codon.org.uk ([217.147.92.49]:37490 "EHLO vavatch.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755469AbXGDO6b (ORCPT ); Wed, 4 Jul 2007 10:58:31 -0400 Date: Wed, 4 Jul 2007 15:58:18 +0100 From: Matthew Garrett To: Alan Stern Cc: linux-kernel@vger.kernel.org, linux-pm@lists.linux-foundation.org Message-ID: <20070704145818.GA7784@srcf.ucam.org> References: <20070703224215.GA30081@srcf.ucam.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.12-2006-07-14 X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: mjg59@codon.org.uk Subject: Re: [linux-pm] [PATCH] Remove process freezer from suspend to RAM pathway X-SA-Exim-Version: 4.2.1 (built Tue, 20 Jun 2006 01:35:45 +0000) X-SA-Exim-Scanned: Yes (on vavatch.codon.org.uk) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 04, 2007 at 10:38:47AM -0400, Alan Stern wrote: > Okay, I agree that (1) can be handled without too much effort. But > doing it adds an extra test to _every_ driver's I/O pathway. Freezing > userspace does not incur all this additional overhead. For runtime PM to work it's already necessary to have a test in that path to check if the device is suspended. I can't see how this adds any overhead to the common case. -- Matthew Garrett | mjg59@srcf.ucam.org