From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752451AbcKGJUh (ORCPT ); Mon, 7 Nov 2016 04:20:37 -0500 Received: from mx2.suse.de ([195.135.220.15]:41623 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751503AbcKGJUg (ORCPT ); Mon, 7 Nov 2016 04:20:36 -0500 Date: Mon, 7 Nov 2016 10:20:31 +0100 From: Borislav Petkov To: Ingo Molnar Cc: x86@kernel.org, Yazen Ghannam , linux-kernel@vger.kernel.org, Peter Zijlstra Subject: Re: [PATCH v3 1/2] x86/AMD: Fix cpu_llc_id for AMD Fam17h systems Message-ID: <20161107092031.alxfkr6rpctodbdk@pd.tnic> References: <1478019063-2632-1-git-send-email-Yazen.Ghannam@amd.com> <20161102201321.slgzk2x2ya4jzfax@pd.tnic> <20161107073121.GB26938@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20161107073121.GB26938@gmail.com> User-Agent: NeoMutt/20161014 (1.7.1) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 07, 2016 at 08:31:21AM +0100, Ingo Molnar wrote: > > cpu_llc_id (Last Level Cache ID) derivation on AMD Fam17h has an > > underflow bug when extracting the socket_id value. It starts from 0 How's this... > > so subtracting 1 from it will result in an invalid value. This breaks > > scheduling topology later on since the cpu_llc_id will be incorrect. ^^^^^^^^^^^^^^^^^^^ ... here? > Same question as for the previous patch: what are the effects of the bug: See above. -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --