From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D38B5C433B4 for ; Tue, 11 May 2021 20:48:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9CDB06162B for ; Tue, 11 May 2021 20:48:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230137AbhEKUt2 (ORCPT ); Tue, 11 May 2021 16:49:28 -0400 Received: from elvis.franken.de ([193.175.24.41]:50409 "EHLO elvis.franken.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229809AbhEKUtV (ORCPT ); Tue, 11 May 2021 16:49:21 -0400 Received: from uucp (helo=alpha) by elvis.franken.de with local-bsmtp (Exim 3.36 #1) id 1lgZIb-0003nj-00; Tue, 11 May 2021 22:48:13 +0200 Received: by alpha.franken.de (Postfix, from userid 1000) id 20819C0E13; Tue, 11 May 2021 22:40:52 +0200 (CEST) Date: Tue, 11 May 2021 22:40:52 +0200 From: Thomas Bogendoerfer To: Mike Rapoport Cc: linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, Mike Rapoport Subject: Re: [RFT PATCH] MIPS: Octeon: drop dependency on CONFIG_HOLES_IN_ZONE Message-ID: <20210511204052.GA18185@alpha.franken.de> References: <20210418093512.668-1-rppt@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210418093512.668-1-rppt@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Apr 18, 2021 at 12:35:12PM +0300, Mike Rapoport wrote: > From: Mike Rapoport > > CAVIUM_OCTEON_SOC configuration selects HOLES_IN_ZONE option to cope with > memory crashes that were happening in 2011. > > This option effectively aliases pfn_valid_within() to pfn_valid() when > enabled and hardwires it to 1 when disabled. The check for > pfn_valid_within() is only relevant in case the memory map may have holes > or undefined struct page instances inside MAX_ORDER chunks. > > Since 2011 memory management initialization in general and memory map > initialization particularly became much more robust so the check for > pfn_valid_within() is not required on Octeon even despite its, hmm, unusual > memory setup. > > Remove the selection of HOLES_IN_ZONE by CAVIUM_OCTEON_SOC and drop the > HOLES_IN_ZONE configuration option entirely as Octeon was the only MIPS > platform to use it. > > Signed-off-by: Mike Rapoport > --- > > Hi, > > I've tried to find why Octeon needed CONFIG_HOLES_IN_ZONE in the first > place, but there is nothing except the changelog in commit 465aaed0030b > ("MIPS: Octeon: Select CONFIG_HOLES_IN_ZONE"): > > Current Octeon systems do in fact have holes in their memory zones. > We need to select HOLES_IN_ZONE. If we do not, some memory configurations > will result in crashes at boot time > > Since then there were too many changes around memory management > initialization both in the generic mm and on the MIPS side to track what > exactly could case the crashes. > > I'm pretty confident that HOLES_IN_ZONE is not required for Octeon systems > anymore and can be removed. > > I'd really appreciate if somebody with access to an Octeon system could > test this patch. > > arch/mips/Kconfig | 4 ---- > 1 file changed, 4 deletions(-) applied to mips-next. Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]