Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934151AbaGXFYA (ORCPT ); Thu, 24 Jul 2014 01:24:00 -0400 Received: from mga03.intel.com ([143.182.124.21]:54333 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934044AbaGXFX6 convert rfc822-to-8bit (ORCPT ); Thu, 24 Jul 2014 01:23:58 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,721,1400050800"; d="scan'208";a="460728446" From: "Ren, Qiaowei" To: "Hansen, Dave" , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar CC: "x86@kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" Subject: RE: [PATCH v7 03/10] x86, mpx: add macro cpu_has_mpx Thread-Topic: [PATCH v7 03/10] x86, mpx: add macro cpu_has_mpx Thread-Index: AQHPpKaZ7P+lz+nalUOxAx0M9XXWLpurwdcAgAEwxJCAAFzbgIABGsRg//+60gCAAI6pYA== Date: Thu, 24 Jul 2014 05:23:54 +0000 Message-ID: <9E0BE1322F2F2246BD820DA9FC397ADE017042F5@shsmsx102.ccr.corp.intel.com> References: <1405921124-4230-1-git-send-email-qiaowei.ren@intel.com> <1405921124-4230-4-git-send-email-qiaowei.ren@intel.com> <53CE8EEC.2090402@intel.com> <9E0BE1322F2F2246BD820DA9FC397ADE0170079E@shsmsx102.ccr.corp.intel.com> <53CFDC79.8040804@intel.com> <9E0BE1322F2F2246BD820DA9FC397ADE01703028@shsmsx102.ccr.corp.intel.com> <53D08FA4.4030700@intel.com> In-Reply-To: <53D08FA4.4030700@intel.com> Accept-Language: zh-CN, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014-07-24, Hansen, Dave wrote: > On 07/23/2014 05:56 PM, Ren, Qiaowei wrote: >> On 2014-07-24, Hansen, Dave wrote: >>> On 07/22/2014 07:35 PM, Ren, Qiaowei wrote: >>>> The checking about MPX feature should be as follow: >>>> >>>> if (pcntxt_mask & XSTATE_EAGER) { >>>> if (eagerfpu == DISABLE) { >>>> pr_err("eagerfpu not present, disabling > some >>> xstate features: 0x%llx\n", >>>> pcntxt_mask & >>> XSTATE_EAGER); >>>> pcntxt_mask &= ~XSTATE_EAGER; } else { >>>> eagerfpu = ENABLE; >>>> } >>>> } >>>> This patch was merged into kernel the ending of last year >>>> (https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/c >>>> om >>>> mi >>>> t/?id=e7d820a5e549b3eb6c3f9467507566565646a669 ) >>> >>> Should we be doing a clear_cpu_cap(X86_FEATURE_MPX) in here? >>> >>> This isn't major, but I can't _ever_ imagine a user being able to >>> track down why MPX is not working from this message. Should we >>> spruce it up somehow? >> >> Maybe. If the error log "disabling some xstate features:" is changed >> to "disabling MPX xstate features:", do you think it is OK? > > That's better. Is it really disabling MPX, though? > > And shouldn't we clear the cpu feature bit too? I am not sure. I am suspecting whether this checking should be moved before xstate_enable(). Peter, what do you think of it? Thanks, Qiaowei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/