From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f69.google.com (mail-oi0-f69.google.com [209.85.218.69]) by kanga.kvack.org (Postfix) with ESMTP id 7DFEC6B2A5E for ; Thu, 23 Aug 2018 09:41:10 -0400 (EDT) Received: by mail-oi0-f69.google.com with SMTP id p11-v6so4793755oih.17 for ; Thu, 23 Aug 2018 06:41:10 -0700 (PDT) Received: from foss.arm.com (usa-sjc-mx-foss1.foss.arm.com. [217.140.101.70]) by mx.google.com with ESMTP id o132-v6si3151107oih.401.2018.08.23.06.41.09 for ; Thu, 23 Aug 2018 06:41:09 -0700 (PDT) Date: Thu, 23 Aug 2018 14:41:05 +0100 From: Will Deacon Subject: Re: [RFC PATCH 2/2] mm: mmu_notifier fix for tlb_end_vma Message-ID: <20180823134104.GD1496@brain-police> References: <20180823084709.19717-1-npiggin@gmail.com> <20180823084709.19717-3-npiggin@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180823084709.19717-3-npiggin@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Nicholas Piggin Cc: Peter Zijlstra , torvalds@linux-foundation.org, luto@kernel.org, x86@kernel.org, bp@alien8.de, riel@surriel.com, jannh@google.com, ascannell@google.com, dave.hansen@intel.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, David Miller , Martin Schwidefsky , Michael Ellerman , linux-arch@vger.kernel.org On Thu, Aug 23, 2018 at 06:47:09PM +1000, Nicholas Piggin wrote: > The generic tlb_end_vma does not call invalidate_range mmu notifier, > and it resets resets the mmu_gather range, which means the notifier > won't be called on part of the range in case of an unmap that spans > multiple vmas. > > ARM64 seems to be the only arch I could see that has notifiers and > uses the generic tlb_end_vma. I have not actually tested it. > > Signed-off-by: Nicholas Piggin > --- > include/asm-generic/tlb.h | 17 +++++++++++++---- > mm/memory.c | 10 ---------- > 2 files changed, 13 insertions(+), 14 deletions(-) I think we only use the notifiers in the KVM code, which appears to leave the ->invalidate_range() callback empty, so that at least explains why we haven't run into problems here. But the change looks correct to me, so: Acked-by: Will Deacon Thanks, Will