From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756218AbcHBXMo (ORCPT ); Tue, 2 Aug 2016 19:12:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57826 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752316AbcHBXMg (ORCPT ); Tue, 2 Aug 2016 19:12:36 -0400 Date: Tue, 2 Aug 2016 19:12:30 -0400 From: Rafael Aquini To: Nadav Amit Cc: LKML , "open list:MEMORY MANAGEMENT" , X86 ML , Andy Lutomirski , Andrea Arcangeli , lwoodman@redhat.com, Rik van Riel , Mel Gorman , akpm@linux-foundation.org Subject: Re: [PATCH] x86/mm: Add barriers and document switch_mm()-vs-flush synchronization follow-up Message-ID: <20160802231229.GE32028@t510> References: <88fb045963d1e51cd14c05c9c4d283a1ccd29c80.1470151425.git.aquini@redhat.com> <746D30E7-2F58-42DB-95D8-D50922CAEB7E@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <746D30E7-2F58-42DB-95D8-D50922CAEB7E@gmail.com> User-Agent: Mutt/1.6.1 (2016-04-27) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Tue, 02 Aug 2016 23:12:35 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 02, 2016 at 03:27:06PM -0700, Nadav Amit wrote: > Rafael Aquini wrote: > > > While backporting 71b3c126e611 ("x86/mm: Add barriers and document switch_mm()-vs-flush synchronization") > > we stumbled across a possibly missing barrier at flush_tlb_page(). > > I too noticed it and submitted a similar patch that never got a response [1]. > As far as I understood Andy's rationale for the original patch you need a full memory barrier there in flush_tlb_page to get that cache-eviction race sorted out. Regards, -- Rafael