Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758954Ab3IBSlr (ORCPT ); Mon, 2 Sep 2013 14:41:47 -0400 Received: from mail-ie0-f173.google.com ([209.85.223.173]:44814 "EHLO mail-ie0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758880Ab3IBSlp (ORCPT ); Mon, 2 Sep 2013 14:41:45 -0400 MIME-Version: 1.0 In-Reply-To: <1378117829-9095-3-git-send-email-tangchen@cn.fujitsu.com> References: <1378117829-9095-1-git-send-email-tangchen@cn.fujitsu.com> <1378117829-9095-3-git-send-email-tangchen@cn.fujitsu.com> Date: Mon, 2 Sep 2013 11:41:44 -0700 X-Google-Sender-Auth: rTglT38Zq0EzgopskT17QpyWqgk Message-ID: Subject: Re: [PATCH RESEND 2/3] x86, mm: Update min_pfn_mapped in add_pfn_range_mapped(). From: Yinghai Lu To: Tang Chen Cc: Ingo Molnar , "H. Peter Anvin" , Pekka Enberg , Jacob Shin , Thomas Gleixner , Len Brown , "Rafael J. Wysocki" , Linux Kernel Mailing List , ACPI Devel Maling List , "the arch/x86 maintainers" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2433 Lines: 60 On Mon, Sep 2, 2013 at 3:30 AM, Tang Chen wrote: > In current kernel, we update min_pfn_mapped and max_pfn_mapped like this: > > init_mem_mapping() > { > while ( a loop iterates all memory ranges ) { > init_range_memory_mapping(); > |->init_memory_mapping() > |->kernel_physical_mapping_init() > |->add_pfn_range_mapped() > |-> update max_pfn_mapped; > > update min_pfn_mapped; > } > } > > max_pfn_mapped is updated in add_pfn_range_mapped() when a range of memory > is mapped. But min_pfn_mapped is updated in init_mem_mapping(). We can also > update min_pfn_mapped in add_pfn_range_mapped(). > > Signed-off-by: Tang Chen > --- > arch/x86/mm/init.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c > index 5b2eaca..a97749f 100644 > --- a/arch/x86/mm/init.c > +++ b/arch/x86/mm/init.c > @@ -313,6 +313,7 @@ static void add_pfn_range_mapped(unsigned long start_pfn, unsigned long end_pfn) > nr_pfn_mapped = clean_sort_range(pfn_mapped, E820_X_MAX); > > max_pfn_mapped = max(max_pfn_mapped, end_pfn); > + min_pfn_mapped = min(min_pfn_mapped, start_pfn); > } > > bool pfn_range_is_mapped(unsigned long start_pfn, unsigned long end_pfn) > @@ -442,7 +443,6 @@ void __init init_mem_mapping(void) > new_mapped_ram_size = init_range_memory_mapping(start, > last_start); > last_start = start; > - min_pfn_mapped = last_start >> PAGE_SHIFT; > /* only increase step_size after big range get mapped */ > if (new_mapped_ram_size > mapped_ram_size) > step_size <<= STEP_SIZE_SHIFT; Nak, you can not move that. min_pfn_mapped should not be updated before init_range_memory_mapping is returned. as it need to refer old min_pfn_mapped. and init_range_memory_mapping still init mapping from low to high locally. min_pfn_mapped can not be updated too early. Yinghai -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/