From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f200.google.com (mail-pf1-f200.google.com [209.85.210.200]) by kanga.kvack.org (Postfix) with ESMTP id 4B6B56B75E3 for ; Wed, 5 Sep 2018 20:36:23 -0400 (EDT) Received: by mail-pf1-f200.google.com with SMTP id b69-v6so4851155pfc.20 for ; Wed, 05 Sep 2018 17:36:23 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id 60-v6sor452606plb.67.2018.09.05.17.36.21 for (Google Transport Security); Wed, 05 Sep 2018 17:36:22 -0700 (PDT) Subject: Re: [PATCH 3/3] mm: optimise pte dirty/accessed bit setting by demand based pte insertion References: <20180828112034.30875-1-npiggin@gmail.com> <20180828112034.30875-4-npiggin@gmail.com> <20180905142951.GA15680@roeck-us.net> <20180906081802.210984d7@roar.ozlabs.ibm.com> From: Guenter Roeck Message-ID: Date: Wed, 5 Sep 2018 17:36:18 -0700 MIME-Version: 1.0 In-Reply-To: <20180906081802.210984d7@roar.ozlabs.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Nicholas Piggin Cc: linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Andrew Morton , Linus Torvalds , Ley Foon Tan , nios2-dev@lists.rocketboards.org On 09/05/2018 03:18 PM, Nicholas Piggin wrote: > On Wed, 5 Sep 2018 07:29:51 -0700 > Guenter Roeck wrote: > >> Hi, >> >> On Tue, Aug 28, 2018 at 09:20:34PM +1000, Nicholas Piggin wrote: >>> Similarly to the previous patch, this tries to optimise dirty/accessed >>> bits in ptes to avoid access costs of hardware setting them. >>> >> >> This patch results in silent nios2 boot failures, silent meaning that >> the boot stalls. >> >> ... >> Unpacking initramfs... >> Freeing initrd memory: 2168K >> workingset: timestamp_bits=30 max_order=15 bucket_order=0 >> jffs2: version 2.2. (NAND) A(C) 2001-2006 Red Hat, Inc. >> random: fast init done >> random: crng init done >> >> [no further activity until the qemu session is aborted] >> >> Reverting the patch fixes the problem. Bisect log is attached. > > Thanks for bisecting it, I'll try to reproduce. Just qemu with no > obscure options? Interesting that it's hit nios2 but apparently not > other archs (yet). > Nothing special. See https://github.com/groeck/linux-build-test/tree/master/rootfs/nios2/. Guenter