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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39F3FECAAD1 for ; Thu, 1 Sep 2022 17:59:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234005AbiIAR7i (ORCPT ); Thu, 1 Sep 2022 13:59:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40072 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233908AbiIAR7e (ORCPT ); Thu, 1 Sep 2022 13:59:34 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69569786FD for ; Thu, 1 Sep 2022 10:59:32 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id D0AF9B8259D for ; Thu, 1 Sep 2022 17:59:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6ED34C433C1; Thu, 1 Sep 2022 17:59:27 +0000 (UTC) Date: Thu, 1 Sep 2022 18:59:23 +0100 From: Catalin Marinas To: kernel test robot Cc: Peter Collingbourne , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kbuild-all@lists.01.org, Cornelia Huck , Will Deacon , Marc Zyngier , Evgenii Stepanov , kvm@vger.kernel.org, Steven Price , Vincenzo Frascino Subject: Re: [PATCH v3 3/7] mm: Add PG_arch_3 page flag Message-ID: References: <20220810193033.1090251-4-pcc@google.com> <202208111500.62e0Bl2l-lkp@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202208111500.62e0Bl2l-lkp@intel.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, Aug 11, 2022 at 03:16:08PM +0800, kernel test robot wrote: > Thank you for the patch! Perhaps something to improve: > > [auto build test WARNING on arm64/for-next/core] > [also build test WARNING on linus/master next-20220811] > [cannot apply to kvmarm/next arm/for-next soc/for-next xilinx-xlnx/master v5.19] > [If your patch is applied to the wrong git tree, kindly drop us a note. > And when submitting patch, we suggest to use '--base' as documented in > https://git-scm.com/docs/git-format-patch#_base_tree_information] > > url: https://github.com/intel-lab-lkp/linux/commits/Peter-Collingbourne/KVM-arm64-permit-MAP_SHARED-mappings-with-MTE-enabled/20220811-033310 > base: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core > config: loongarch-defconfig (https://download.01.org/0day-ci/archive/20220811/202208111500.62e0Bl2l-lkp@intel.com/config) > compiler: loongarch64-linux-gcc (GCC) 12.1.0 > reproduce (this is a W=1 build): > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > # https://github.com/intel-lab-lkp/linux/commit/1a400517d8428df0ec9f86f8d303b2227ee9702f > git remote add linux-review https://github.com/intel-lab-lkp/linux > git fetch --no-tags linux-review Peter-Collingbourne/KVM-arm64-permit-MAP_SHARED-mappings-with-MTE-enabled/20220811-033310 > git checkout 1a400517d8428df0ec9f86f8d303b2227ee9702f > # save the config file > mkdir build_dir && cp config build_dir/.config > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=loongarch SHELL=/bin/bash > > If you fix the issue, kindly add following tag where applicable > Reported-by: kernel test robot > > All warnings (new ones prefixed by >>): > > >> mm/memory.c:92:2: warning: #warning Unfortunate NUMA and NUMA Balancing config, growing page-frame for last_cpupid. [-Wcpp] > 92 | #warning Unfortunate NUMA and NUMA Balancing config, growing page-frame for last_cpupid. > | ^~~~~~~ > > > vim +92 mm/memory.c > > 42b7772812d15b Jan Beulich 2008-07-23 90 > af27d9403f5b80 Arnd Bergmann 2018-02-16 91 #if defined(LAST_CPUPID_NOT_IN_PAGE_FLAGS) && !defined(CONFIG_COMPILE_TEST) > 90572890d20252 Peter Zijlstra 2013-10-07 @92 #warning Unfortunate NUMA and NUMA Balancing config, growing page-frame for last_cpupid. > 75980e97daccfc Peter Zijlstra 2013-02-22 93 #endif > 75980e97daccfc Peter Zijlstra 2013-02-22 94 It looks like ith CONFIG_NUMA_BALANCING=y on loongarch we run out of spare bits in page->flags to fit last_cpupid. The reason we don't see it on arm64 is that we select SPARSEMEM_VMEMMAP and SECTIONS_WIDTH becomes 0. On loongarch SECTIONS_WIDTH takes 19 bits (48 - 29) in page->flags. I think instead of always defining PG_arch_{2,3} if CONFIG_64BIT, we could add a CONFIG_ARCH_WANTS_PG_ARCH_23 option and only select it on arm64 for the time being. -- Catalin