Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755695AbcCOLAj (ORCPT ); Tue, 15 Mar 2016 07:00:39 -0400 Received: from mail.skyhub.de ([78.46.96.112]:35302 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750793AbcCOLAb (ORCPT ); Tue, 15 Mar 2016 07:00:31 -0400 Date: Tue, 15 Mar 2016 12:00:05 +0100 From: Borislav Petkov To: Toshi Kani Cc: "mingo@kernel.org" , "hpa@zytor.com" , "tglx@linutronix.de" , "mcgrof@suse.com" , "jgross@suse.com" , "paul.gortmaker@windriver.com" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 1/2] x86/mm/pat: Change pat_disable() to emulate PAT table Message-ID: <20160315110005.GB4559@pd.tnic> References: <1457671546-13486-1-git-send-email-toshi.kani@hpe.com> <1457671546-13486-2-git-send-email-toshi.kani@hpe.com> <20160311091229.GA4347@pd.tnic> <1457713660.6393.55.camel@hpe.com> <20160311155439.GF4312@pd.tnic> <1457724504.6393.151.camel@hpe.com> <20160312115544.GA23410@pd.tnic> <1457991443.6393.290.camel@hpe.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1457991443.6393.290.camel@hpe.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1938 Lines: 52 On Mon, Mar 14, 2016 at 03:37:23PM -0600, Toshi Kani wrote: > Your patch is a simplified version of mine.  So, yes, it fixes the Paul's > issue, but it does not address other issues that my patchset also > addressed.  In specific, I think your patch has the following issues. You couldnt've structured your reply better: remember how I split a convoluted patch of yours already? A patch which was trying to do a bunch of things in one go. The situation here is the same. You need to do *one* *logical* *non-trivial* thing in a patch. If there's something else that needs to be done, add it in a *separate* patch which explains why that new change is needed. > - pat_disable() is now callable from other modules. So, it needs to check > with boot_cpu_done. We cannot disable PAT once it is initialized. That should be a separate patch which explains *why* the change is being done. > - mtrr_bp_init() needs to check with mtrr_enabled() when it > calls mtrr_pat_setup_bp(). Otherwise, PAT is left initialized on BSP only > when MTRR is disabled by its MSR. In your patch, mtrr_bp_init() calls > pat_setup() again, but it does not help since boot_cpu_done is set. The code which you carved out from get_mtrr_state() didn't check mtrr_enabled() before. That needs to be another patch *again* with explanations. > - When PAT is disabled in CPU feature, pat_bsp_init() calls pat_disable() > and returns. However, it does not initialize a PAT table by calling > pat_init_cache_modes(). Yet another patch. > - When CONFIG_MTRR is unset, it does not call pat_setup(). Aaaand... can you guess what I'm going to say here? I hope it is coming across as I intend it: please use my hunk to do a single fix and then prepare all those changes above in separate patches with explanations: "Problem is A. We need to do B. I'm doing it/I'm doing C because." Ok? -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply.