From: Linus Torvalds Subject: Re: [PATCH 1/1] x86: fix text_poke Date: Fri, 25 Apr 2008 10:29:36 -0700 (PDT) Message-ID: References: <20080425152650.GA894@elte.hu> <20080425154854.GC3265@one.firstfloor.org> <20080425162215.GA16273@elte.hu> <20080425164509.GB19962@elte.hu> <20080425170237.GA24472@elte.hu> <20080425172651.GF3265@one.firstfloor.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Ingo Molnar , Jiri Slaby , David Miller , zdenek.kabelac@gmail.com, rjw@sisk.pl, paulmck@linux.vnet.ibm.com, akpm@linux-foundation.org, linux-ext4@vger.kernel.org, herbert@gondor.apana.org.au, penberg@cs.helsinki.fi, clameter@sgi.com, linux-kernel@vger.kernel.org, Mathieu Desnoyers , pageexec@freemail.hu, "H. Peter Anvin" , Jeremy Fitzhardinge To: Andi Kleen Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:49251 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760447AbYDYRc0 (ORCPT ); Fri, 25 Apr 2008 13:32:26 -0400 In-Reply-To: <20080425172651.GF3265@one.firstfloor.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Fri, 25 Apr 2008, Andi Kleen wrote: > > For suspend/resume we can actually just disable all the text_poke()s. > They are not needed because we don't expect to stay in single CPU > mode for long after wake up and they will just be undone again. I do agree that we might decide to just not do this at all except for the actual physical bootup phase (which can use early_text_poke()). There may not be a whole lot of point to ever play with smp_alterinatives() at any other time. > I guess if it really was a problem (but really I haven't heard about it) > the easiest fix would be to just extended system_state to SYSTEM_SUSPEND > and then skip them if that is true. Our device suspend right now takes about 3.5 seconds (that's using the debug thing, which adds a 5-second timeout). That *is* a problem, but it's historically been hidden by the fact that people are happy that suspend works at all when it does. These days, we're getting to the point (I think) that a lot more people are going to take suspend for granted. And I'd actually like to use it as a sleep state for desktop like usage (let's face it, when the screen goes dark, the CPU should just go into suspend too if it's used as a desktop by non-technical users). And for that to be useful, it needs to come up quickly. Not add another second on top of the already-irritating delay of the screen waking up. Are we there yet? Hell no. But I don't think we're too far off. Linus