Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756618AbcJMQGI (ORCPT ); Thu, 13 Oct 2016 12:06:08 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:58415 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756570AbcJMQFt (ORCPT ); Thu, 13 Oct 2016 12:05:49 -0400 Date: Thu, 13 Oct 2016 17:36:30 +0200 (CEST) From: Thomas Gleixner To: Grzegorz Andrejczuk cc: mingo@redhat.com, hpa@zytor.com, x86@kernel.org, bp@suse.de, dave.hansen@linux.intel.com, linux-kernel@vger.kernel.org, lukasz.daniluk@intel.com, james.h.cownie@intel.com, jacob.jun.pan@intel.com Subject: Re: [PATCH v3 3/4] Add hwcap2 for x86 In-Reply-To: <1476367345-25628-4-git-send-email-grzegorz.andrejczuk@intel.com> Message-ID: References: <1476367345-25628-1-git-send-email-grzegorz.andrejczuk@intel.com> <1476367345-25628-4-git-send-email-grzegorz.andrejczuk@intel.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) 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 Content-Length: 649 Lines: 23 On Thu, 13 Oct 2016, Grzegorz Andrejczuk wrote: > Add hwcap2 attribute for x86. Great value in repeating the subject line. And the subject line is crap because this patch does way more than adding hwcap2 .... > Reserve 1st bit of HWCAP2 for exposing Xeon Phi ring 3 monitor/mwait. > With this userspace apps can detect Ring 3 MONITOR/MWAIT instructions. User space cannot detect the instructions. User space can check whether the instructions are enabled. > +/* Kernel enabled Ring 3 MWAIT for Xeon Phi*/ > +#define HWCAP2_PHIR3MWAIT (1 << 0) > +/* upto bit 31 free */ Very useful comment, NOT! Stop documenting the obvious. Thanks, tglx