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=-5.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_NEOMUTT autolearn=ham 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 56609ECE560 for ; Sun, 16 Sep 2018 15:01:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 04B5120883 for ; Sun, 16 Sep 2018 15:01:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 04B5120883 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728266AbeIPUY6 (ORCPT ); Sun, 16 Sep 2018 16:24:58 -0400 Received: from mga12.intel.com ([192.55.52.136]:24399 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726852AbeIPUY6 (ORCPT ); Sun, 16 Sep 2018 16:24:58 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Sep 2018 08:01:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,381,1531810800"; d="scan'208";a="86540491" Received: from shbuild888.sh.intel.com (HELO localhost) ([10.239.146.239]) by fmsmga002.fm.intel.com with ESMTP; 16 Sep 2018 08:01:42 -0700 Date: Sun, 16 Sep 2018 23:06:41 +0800 From: Feng Tang To: Thomas Gleixner Cc: Michal Hocko , Peter Zijlstra , LKML , x86@kernel.org, Ingo Molnar , "H . Peter Anvin" , Yinghai Lu , Dave Hansen , Andi Kleen Subject: Re: [PATCH] x86, mm: Reserver some memory for bootmem allocator for NO_BOOTMEM Message-ID: <20180916150641.qvlfseyeue5vij4w@shbuild888> References: <20180907081716.bxw3hmcl6w7gqvax@shbuild888> <20180910093938.ka732apzy3d3a5ip@shbuild888> <20180911061413.redy4oxia3hqifkh@shbuild888> <20180915164731.3zrdxijuwkgdi25p@shbuild888> <20180916143549.zmnlcviyn67fbxwh@shbuild888> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Thomas, On Sun, Sep 16, 2018 at 04:43:55PM +0200, Thomas Gleixner wrote: > On Sun, 16 Sep 2018, Feng Tang wrote: > > diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c > > index e848a4811785..a927f5f39bee 100644 > > --- a/arch/x86/mm/pgtable.c > > +++ b/arch/x86/mm/pgtable.c > > @@ -637,6 +637,16 @@ void __native_set_fixmap(enum fixed_addresses idx, pte_t pte) > > { > > unsigned long address = __fix_to_virt(idx); > > > > +#ifdef CONFIG_X86_64 > > + /* > > + * In arch/x86/kernel/head_64.S, the static page table has > > + * been setup for fixmap. Add a sanity compiling check > > + * whether fixmap space has exceeded the capacity. > > + */ > > + BUILD_BUG_ON((__end_of_permanent_fixed_addresses + 511)/512 > > + > FIXMAP_PMD_NUM); > > There exist macros for rounding up and doing this in the header file is > perfectly fine. I'll find the sample for the round up. And for the header file check, I initially put this check directly in the fixmap.h like: #if ((__end_of_permanent_fixed_addresses + 511)/512 > FIXMAP_PMD_NUM) #erro "some warning...." #endif But failed to compile, I got the warning warning: "__end_of_permanent_fixed_addresses" is not defined I guess the header file preprocessing can't handle it. > > > +#endif > > + > > if (idx >= __end_of_fixed_addresses) { > > BUG(); > > return; > > diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c > > index 45b700ac5fe7..b0aa2364a3c6 100644 > > --- a/arch/x86/xen/mmu_pv.c > > +++ b/arch/x86/xen/mmu_pv.c > > @@ -1953,7 +1953,10 @@ void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn) > > set_page_prot(level2_ident_pgt, PAGE_KERNEL_RO); > > set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO); > > set_page_prot(level2_fixmap_pgt, PAGE_KERNEL_RO); > > - set_page_prot(level1_fixmap_pgt, PAGE_KERNEL_RO); > > + > > + for (i = 0; i < FIXMAP_PMD_NUM; i++) > > + set_page_prot(level1_fixmap_pgt + i * 512, > > + PAGE_KERNEL_RO); > > The line break is there because? Will fix it. I used a MACRO before changing to 512 and forgot to remove the line break :) Thanks, Feng