From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753215AbcGMK2Y (ORCPT ); Wed, 13 Jul 2016 06:28:24 -0400 Received: from www.linutronix.de ([62.245.132.108]:38214 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751947AbcGMK2P (ORCPT ); Wed, 13 Jul 2016 06:28:15 -0400 Date: Wed, 13 Jul 2016 12:25:39 +0200 (CEST) From: Thomas Gleixner To: Fenghua Yu cc: Ingo Molnar , "H. Peter Anvin" , Tony Luck , Tejun Heo , Borislav Petkov , Stephane Eranian , Peter Zijlstra , Marcelo Tosatti , David Carrillo-Cisneros , Ravi V Shankar , Vikas Shivappa , Sai Prakhya , linux-kernel , x86 Subject: Re: [PATCH 08/32] Define CONFIG_INTEL_RDT In-Reply-To: <1468371785-53231-9-git-send-email-fenghua.yu@intel.com> Message-ID: References: <1468371785-53231-1-git-send-email-fenghua.yu@intel.com> <1468371785-53231-9-git-send-email-fenghua.yu@intel.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001,URIBL_BLOCKED=0.001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 12 Jul 2016, Fenghua Yu wrote: Subject: Define CONFIG_INTEL_RDT That does not qualify as a proper patch subject > From: Vikas Shivappa > > CONFIG_INTEL_RDT is defined. That tells us what? > --- a/arch/x86/include/asm/intel_rdt.h > +++ b/arch/x86/include/asm/intel_rdt.h > @@ -24,8 +24,16 @@ struct clos_cbm_table { > * on scheduler hot path: > * - This will stay as no-op unless we are running on an Intel SKU > * which supports L3 cache allocation. > + * - When support is present and enabled, does not do any > + * IA32_PQR_MSR writes until the user starts really using the feature > + * ie creates a rdtgroup directory and assigns a cache_mask thats > + * different from the root rdtgroup's cache_mask. > * - Caches the per cpu CLOSid values and does the MSR write only > - * when a task with a different CLOSid is scheduled in. > + * when a task with a different CLOSid is scheduled in. That > + * means the task belongs to a different rdtgroup. > + * - Closids are allocated so that different rdtgroup directories > + * with same cache_mask gets the same CLOSid. This minimizes CLOSids > + * used and reduces MSR write frequency. How is this and the following changes related to $subject ? Thanks, tglx