Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934992Ab0HFRda (ORCPT ); Fri, 6 Aug 2010 13:33:30 -0400 Received: from opensource.wolfsonmicro.com ([80.75.67.52]:54748 "EHLO opensource2.wolfsonmicro.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751713Ab0HFRd2 (ORCPT ); Fri, 6 Aug 2010 13:33:28 -0400 Date: Fri, 6 Aug 2010 18:33:25 +0100 From: Mark Brown To: "Paul E. McKenney" Cc: david@lang.hm, Brian Swetland , kevin granade , Arve Hj?nnev?g , Matthew Garrett , "Rafael J. Wysocki" , Arjan van de Ven , linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org, pavel@ucw.cz, florian@mickler.org, stern@rowland.harvard.edu, peterz@infradead.org, tglx@linutronix.de, alan@lxorguk.ukuu.org.uk Subject: Re: Attempted summary of suspend-blockers LKML thread Message-ID: <20100806173325.GA25367@rakim.wolfsonmicro.main> References: <20100805230304.GQ2447@linux.vnet.ibm.com> <20100806123047.GE31326@sirena.org.uk> <20100806172226.GH2432@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100806172226.GH2432@linux.vnet.ibm.com> X-Cookie: An idle mind is worth two in the bush. 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: 1384 Lines: 25 On Fri, Aug 06, 2010 at 10:22:26AM -0700, Paul E. McKenney wrote: > On Fri, Aug 06, 2010 at 01:30:48PM +0100, Mark Brown wrote: > > this (the one following the rename to suspend blockers). Essentially > > what happens in a mainline context is that some subsystems can with > > varying degress of optionality ignore some or all of the instruction to > > suspend and keep bits of the system alive during suspend. > This underscores a basic difference between servers and these embedded > devices. When you suspend a server, it is doing nothing, because servers > rely very heavily on the CPUs. In contrast, many embedded devices can > perform useful work even when the CPUs are completely powered down. Well, not really from the Linux point of view. It's not massively different to something like keeping an ethernet controller sufficiently alive to allow it to provide wake on LAN functionality while the system is suspended in terms of what Linux has to do, and quite a few servers have lights out management systems which aren't a million miles away from the modem on a phone in terms of their relationship with the host computer. -- 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/