Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758775Ab0FVBZG (ORCPT ); Mon, 21 Jun 2010 21:25:06 -0400 Received: from mail-pw0-f46.google.com ([209.85.160.46]:64240 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758711Ab0FVBZD (ORCPT ); Mon, 21 Jun 2010 21:25:03 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:reply-to:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=OWeAFXnAzJCd5JwISXs06ibgvttdcravy1dwawfefietBUk6FkkC6B8o7+XYo1EplO 2JG2k3D/KEX0udDV2gDJxOM6MbvVg7fc4j8F6W+aNzSRxjCmFfTUm7hX37pPZ8ioNKcY Lso8BrnxMEOhx8NjuC22i2vZAiLv4H+SgXE7A= Date: Mon, 21 Jun 2010 18:25:19 -0700 From: mark gross <640e9920@gmail.com> To: Alan Stern Cc: markgross@thegnar.org, "Rafael J. Wysocki" , Linux-pm mailing list , Matthew Garrett , Linux Kernel Mailing List , Dmitry Torokhov , Arve =?iso-8859-1?B?SGr4bm5lduVn?= , Neil Brown , mark gross <640e9920@gmail.com> Subject: Re: [RFC][PATCH] PM: Avoid losing wakeup events during suspend Message-ID: <20100622012519.GB12795@gvim.org> Reply-To: markgross@thegnar.org References: <20100621061345.GF9735@gvim.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1953 Lines: 46 On Mon, Jun 21, 2010 at 12:01:09PM -0400, Alan Stern wrote: > On Sun, 20 Jun 2010, mark gross wrote: > > > Your confused about what problem this patch attempts to solve. > > I don't think so. Rafael's description was pretty clear. Then how is it you don't understand the fact that Rafael's patch is to solve the wake event notification suspend race and not block opertunistic suspends or kernel critical sections where suspending should be disabled? > > > There is > > a pm_qos patch in the works to address the suspend blocker > > functionality. > > http://lists.linux-foundation.org/pipermail/linux-pm/2010-June/026760.html > > No. That patch addresses something _similar_ to the suspend blocker > functionality. The fact remains, though, that pm_qos is not used > during system suspend (the /sys/power/state interface), hence changes > to pm_qos won't solve the system-suspend problems that suspend blockers > do solve. You keep saying they solve something, I keep wondering what you are talking aobut. Lets see what problems it solves: * implements oppertunistic suspending (this is a feature not a problem) * enables kernel critical sections blocking suspending. * requiers overlapping application specific critcal sections from ISR into user mode to make implementation correct. * exposes a user mode interface to set a critical section. * reduces races between wake events (or suspend blocking events) but I'm not convinced it solves them. suspend blockers provide a way to block oppertunistic suspending, wich I'll have you know, is a pain to get working right and the enabling from device to device is not very portable and *that* doesn't say good things about the scheme. --mgross -- 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/