From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f71.google.com (mail-oi0-f71.google.com [209.85.218.71]) by kanga.kvack.org (Postfix) with ESMTP id A82D98E0001 for ; Wed, 19 Sep 2018 08:24:22 -0400 (EDT) Received: by mail-oi0-f71.google.com with SMTP id p11-v6so4852940oih.17 for ; Wed, 19 Sep 2018 05:24:22 -0700 (PDT) Received: from foss.arm.com (foss.arm.com. [217.140.101.70]) by mx.google.com with ESMTP id u185-v6si9210653oib.207.2018.09.19.05.24.21 for ; Wed, 19 Sep 2018 05:24:21 -0700 (PDT) Date: Wed, 19 Sep 2018 13:24:39 +0100 From: Will Deacon Subject: Re: [RFC][PATCH 07/11] arm/tlb: Convert to generic mmu_gather Message-ID: <20180919122439.GC22723@arm.com> References: <20180913092110.817204997@infradead.org> <20180913092812.247989787@infradead.org> <20180918141034.GF16498@arm.com> <20180919112829.GA24124@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180919112829.GA24124@hirez.programming.kicks-ass.net> Sender: owner-linux-mm@kvack.org List-ID: To: Peter Zijlstra Cc: aneesh.kumar@linux.vnet.ibm.com, akpm@linux-foundation.org, npiggin@gmail.com, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux@armlinux.org.uk, heiko.carstens@de.ibm.com On Wed, Sep 19, 2018 at 01:28:29PM +0200, Peter Zijlstra wrote: > On Tue, Sep 18, 2018 at 03:10:34PM +0100, Will Deacon wrote: > > > So whilst I was reviewing this, I realised that I think we should be > > selecting HAVE_RCU_TABLE_INVALIDATE for arch/arm/ if HAVE_RCU_TABLE_FREE. > > Yes very much so. Let me invert that option, you normally want that, > except if you don't natively use the linux page-tables. Yeah, inverting this to be opt-out is definitely the safe thing to do. Patch below looks good: Acked-by: Will Deacon Will > --- > Subject: asm-generic/tlb: Invert HAVE_RCU_TABLE_INVALIDATE > From: Peter Zijlstra > Date: Wed Sep 19 13:24:41 CEST 2018 > > Make issuing a TLB invalidate for page-table pages the normal case. > > The reason is twofold: > > - too many invalidates is safer than too few, > - most architectures use the linux page-tables natively > and would this require this. > > Make it an opt-out, instead of an opt-in. > > Signed-off-by: Peter Zijlstra (Intel)