Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936097Ab3DKPRH (ORCPT ); Thu, 11 Apr 2013 11:17:07 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:16664 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934526Ab3DKPRF (ORCPT ); Thu, 11 Apr 2013 11:17:05 -0400 Message-ID: <5166D3F8.2050901@oracle.com> Date: Thu, 11 Apr 2013 11:17:12 -0400 From: Boris Ostrovsky User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130219 Thunderbird/17.0.3 MIME-Version: 1.0 To: hpa@zytor.com CC: mingo@kernel.org, linux-kernel@vger.kernel.org, konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, jwboyer@redhat.com, tglx@linutronix.de, bp@suse.de Subject: Re: [tip:x86/urgent] x86, mm: Patch out arch_flush_lazy_mmu_mode() when running on bare metal References: <1364045796-10720-2-git-send-email-konrad.wilk@oracle.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1408 Lines: 37 On 04/10/2013 08:30 PM, tip-bot for Boris Ostrovsky wrote: > Commit-ID: 511ba86e1d386f671084b5d0e6f110bb30b8eeb2 > Gitweb: http://git.kernel.org/tip/511ba86e1d386f671084b5d0e6f110bb30b8eeb2 > Author: Boris Ostrovsky > AuthorDate: Sat, 23 Mar 2013 09:36:36 -0400 > Committer: H. Peter Anvin > CommitDate: Wed, 10 Apr 2013 11:25:10 -0700 > > x86, mm: Patch out arch_flush_lazy_mmu_mode() when running on bare metal > > Invoking arch_flush_lazy_mmu_mode() results in calls to > preempt_enable()/disable() which may have performance impact. > > Since lazy MMU is not used on bare metal we can patch away > arch_flush_lazy_mmu_mode() so that it is never called in such > environment. > > [ hpa: the previous patch "Fix vmalloc_fault oops during lazy MMU > updates" may cause a minor performance regression on > bare metal. This patch resolves that performance regression. It is > somewhat unclear to me if this is a good -stable candidate. ] I think this https://lkml.org/lkml/2013/2/26/420 was also part of lazy mmu set of patches but is missing in the latest batch of commits. -boris -- 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/