From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754524Ab2EKAvD (ORCPT ); Thu, 10 May 2012 20:51:03 -0400 Received: from mga14.intel.com ([143.182.124.37]:3939 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751323Ab2EKAvA (ORCPT ); Thu, 10 May 2012 20:51:00 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="98762010" Message-ID: <4FAC621D.2020704@intel.com> Date: Fri, 11 May 2012 08:49:33 +0800 From: Alex Shi User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:9.0) Gecko/20111229 Thunderbird/9.0 MIME-Version: 1.0 To: Peter Zijlstra CC: rob@landley.net, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, arnd@arndb.de, rostedt@goodmis.org, fweisbec@gmail.com, jeremy@goop.org, gregkh@linuxfoundation.org, borislav.petkov@amd.com, riel@redhat.com, luto@mit.edu, avi@redhat.com, len.brown@intel.com, dhowells@redhat.com, fenghua.yu@intel.com, ak@linux.intel.com, cpw@sgi.com, steiner@sgi.com, akpm@linux-foundation.org, penberg@kernel.org, hughd@google.com, rientjes@google.com, kosaki.motohiro@jp.fujitsu.com, n-horiguchi@ah.jp.nec.com, paul.gortmaker@windriver.com, trenn@suse.de, tj@kernel.org, oleg@redhat.com, axboe@kernel.dk, kamezawa.hiroyu@jp.fujitsu.com, viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 5/7] x86/tlb: add tlb flush all factor for specific CPU References: <1336626013-28413-1-git-send-email-alex.shi@intel.com> <1336626013-28413-6-git-send-email-alex.shi@intel.com> <1336642715.2527.84.camel@twins> In-Reply-To: <1336642715.2527.84.camel@twins> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/10/2012 05:38 PM, Peter Zijlstra wrote: > On Thu, 2012-05-10 at 13:00 +0800, Alex Shi wrote: > > >> +void intel_tlb_flushall_factor_set(struct cpuinfo_x86 *c) >> +{ >> + if (!cpu_has_invlpg) { >> + tlb_flushall_factor = -1; >> + return; >> + } > > ... > >> + if (!cpu_has_invlpg || vma->vm_flags & VM_HUGETLB >> + || tlb_flushall_factor == (u16)TLB_FLUSH_ALL) >> { >> flush_all: > > Since you set tlb_flushall_factor (I'd have called it _shift) to -1 > when !invlpg there's a redundant check in there. > NO, the first judgement is from CPU. But second '-1' is may from user setting in sysfs.