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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f72.google.com (mail-oi0-f72.google.com [209.85.218.72]) by kanga.kvack.org (Postfix) with ESMTP id D59F26B0253 for ; Tue, 2 Aug 2016 19:12:36 -0400 (EDT) Received: by mail-oi0-f72.google.com with SMTP id q62so397206468oih.0 for ; Tue, 02 Aug 2016 16:12:36 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id d6si8003053ith.99.2016.08.02.16.12.36 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 02 Aug 2016 16:12:36 -0700 (PDT) Date: Tue, 2 Aug 2016 19:12:30 -0400 From: Rafael Aquini 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> Sender: owner-linux-mm@kvack.org List-ID: 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 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org