From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754537Ab2FMO47 (ORCPT ); Wed, 13 Jun 2012 10:56:59 -0400 Received: from mga11.intel.com ([192.55.52.93]:35919 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754516Ab2FMO45 (ORCPT ); Wed, 13 Jun 2012 10:56:57 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="179480471" Date: Wed, 13 Jun 2012 07:56:56 -0700 From: Andi Kleen To: Alex Shi Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, arnd@arndb.de, rostedt@goodmis.org, fweisbec@gmail.com, jeremy@goop.org, seto.hidetoshi@jp.fujitsu.com, borislav.petkov@amd.com, tony.luck@intel.com, luto@mit.edu, riel@redhat.com, avi@redhat.com, len.brown@intel.com, tj@kernel.org, akpm@linux-foundation.org, cl@gentwo.org, jbeulich@suse.com, eric.dumazet@gmail.com, akinobu.mita@gmail.com, cpw@sgi.com, penberg@kernel.org, steiner@sgi.com, viro@zeniv.linux.org.uk, kamezawa.hiroyu@jp.fujitsu.com, aarcange@redhat.com, rientjes@google.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v8 8/8] x86/tlb: do flush_tlb_kernel_range by 'invlpg' Message-ID: <20120613145656.GB32604@tassilo.jf.intel.com> References: <1339492005-20241-1-git-send-email-alex.shi@intel.com> <1339492005-20241-9-git-send-email-alex.shi@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1339492005-20241-9-git-send-email-alex.shi@intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 12, 2012 at 05:06:45PM +0800, Alex Shi wrote: > This patch do flush_tlb_kernel_range by 'invlpg'. The performance pay > and gain was analyzed in my patch (x86/flush_tlb: try flush_tlb_single > one by one in flush_tlb_range). Now we move this logical into kernel > part. The pay is multiple 'invlpg' execution cost, that is same. but > the gain(cost reducing of TLB entries refilling) is absoulutely > increased. The subtle point is whether INVLPG flushes global pages or not. After some digging I found a sentence in the SDM that says it does. So it may be safe. What does it improve? -Andi