From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760131AbYAVNNS (ORCPT ); Tue, 22 Jan 2008 08:13:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751947AbYAVNNI (ORCPT ); Tue, 22 Jan 2008 08:13:08 -0500 Received: from www.tglx.de ([62.245.132.106]:41737 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750993AbYAVNNG (ORCPT ); Tue, 22 Jan 2008 08:13:06 -0500 Date: Tue, 22 Jan 2008 14:12:32 +0100 (CET) From: Thomas Gleixner To: Andi Kleen cc: Ingo Molnar , linux-kernel@vger.kernel.org, jbeulich@novell.com, venkatesh.pallipadi@intel.com, "H. Peter Anvin" Subject: Re: CPA boot crash (was: [PATCH] [0/36] Great change_page_attr patch series v3) In-Reply-To: <200801211813.45102.ak@suse.de> Message-ID: References: <200801161114.239449000@suse.de> <200801181819.58675.ak@suse.de> <20080121164052.GA11364@elte.hu> <200801211813.45102.ak@suse.de> User-Agent: Alpine 1.00 (LFD 882 2007-12-20) 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 On Mon, 21 Jan 2008, Andi Kleen wrote: > > It's a first shot so it might not yet be perfect - although so far it > > looks good in testing on 4-5 testsystems here, on mixed 64-bit and > > 32-bit boxes. Doing it this way was a pretty straightforward process, it > > took less than an hour - and the end result feels much better in terms > > of maintainability. > > You still kept Venki's redundant 32bit reference count change for 32bit. > The code handled that already by doing reserved bits check. Hmm. Which patch are you referring to ? There is no patch from Venki in x86.git which touches the pageattr code. > IMHO it would have been cleaner to also do that for the 64bit version > instead of abusing the reference counting for this (like my > "CPA Handle 4K split pages at boot on 64bit" patch did). I don't understand what you mean. The "CPA Handle 4K split pages at boot on 64bit" patch is in x86.git: http://git.kernel.org/?p=linux/kernel/git/x86/linux-2.6-x86.git;a=commit;h=360b371f73b96c400c6a8fc19ea334d083c65c92 Please clarify. > > I left the clflush feature bits out for now - fixes and cleanups go > > first. We first need to see whether this is robust enough before making > > other changes to c_p_a(). There's enough on the arch/x86 plate for > > v2.6.25 already - we can try the clflush optimizations in v2.6.26. > > (since there's no high-freq in-kernel user of the c_p_a() API at the > > moment, there's no pressing need for this either.) > > Ok I'll redo it. Thank you for your support. > > Probably in larger chunks now though -- with your somewhat > random patching applying methology larger small grained series are just too > painful for me. Please keep them fine-grained and keep fixes separate and prior to features. > First priority will be gbpages on top of it. First priority is getting CPA and PAT consolidated before we put new functionality on top of it. This implies a possible unification of the 32 and 64 bit code as well. There is no real good reason to have different implementations for those. > I would appreciate if you could either prevent or warn against further > wide scale changes on these files before .26 then -- otherwise I'll have > again play catch up with a relatively large patchkit. FYI, the consolidation of CPA and PAT is changing that code, so flux is expected. Thanks, tglx