Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754577AbZLOP1t (ORCPT ); Tue, 15 Dec 2009 10:27:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757469AbZLOP1o (ORCPT ); Tue, 15 Dec 2009 10:27:44 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:58798 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757128AbZLOP1k (ORCPT ); Tue, 15 Dec 2009 10:27:40 -0500 Date: Tue, 15 Dec 2009 07:26:41 -0800 (PST) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: "Rafael J. Wysocki" cc: Alan Stern , Zhang Rui , LKML , ACPI Devel Maling List , pm list Subject: Re: Async suspend-resume patch w/ completions (was: Re: Async suspend-resume patch w/ rwsems) In-Reply-To: <200912151203.22916.rjw@sisk.pl> Message-ID: References: <200912150018.11837.rjw@sisk.pl> <200912151203.22916.rjw@sisk.pl> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1557 Lines: 46 On Tue, 15 Dec 2009, Rafael J. Wysocki wrote: > > > > Give a real example that matters. > > I'll try. Let -> denote child-parent relationships and assume dpm_list looks > like this: No. I mean something real - something like - if you run on a non-PC with two USB buses behind non-PCI controllers. - device xyz. > If this applies to _resume_ only, then I agree, but the Arjan's data clearly > show that serio devices take much more time to suspend than USB. I mean in general - something where you actually have hard data that some device really needs anythign more than my one-liner, and really _needs_ some complex infrastructure. Not "let's imagine a case like xyz". > But if we only talk about resume, the PCI bridges don't really matter, > because they are resumed before all devices that depend on them, so they don't > really need to wait for anyone anyway. But that's my _point_. That's the whole point of the one-liner patch. Read the comment above that one-liner. My whole point was that by doing the whole "wait for children" in generic code, you also made devices - such as PCI bridges - have to wait for children, even though they don't need to, and don't want to. So I suggested an admittedly ugly hack to take care of it - rather than some complex infrastructure. Linus -- 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/