Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758636AbZGCUIy (ORCPT ); Fri, 3 Jul 2009 16:08:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757365AbZGCUIq (ORCPT ); Fri, 3 Jul 2009 16:08:46 -0400 Received: from qw-out-2122.google.com ([74.125.92.26]:64770 "EHLO qw-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757142AbZGCUIq convert rfc822-to-8bit (ORCPT ); Fri, 3 Jul 2009 16:08:46 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=ia36FifgpfE6VMdfjJIZpHZ1Nyu3pBC/pJVIAkc/npyzSz8/BeqJMwFUNGlYWXK6zI fiREKpUh8ZG65yzdfz3FvYEzMdBrpVV7UcIgV5Wyedd4m4yCEv7/detu122B46LVJrsQ IqN1GugL0BJUPRHX8UY9iJIBpEcGSACyS6BMs= MIME-Version: 1.0 In-Reply-To: <86802c440907031307s43fca3c0j77d4df78450ff757@mail.gmail.com> References: <200907031314.36243.lkml@morethan.org> <86802c440907031307s43fca3c0j77d4df78450ff757@mail.gmail.com> Date: Fri, 3 Jul 2009 13:08:49 -0700 Message-ID: <86802c440907031308j3f996db6g9dfb1b8f9ccb7e7f@mail.gmail.com> Subject: Re: [Bug Fix]: Do 32-bit table calculations in pre-processor From: Yinghai Lu To: lkml@morethan.org Cc: linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2196 Lines: 57 On Fri, Jul 3, 2009 at 1:07 PM, Yinghai Lu wrote: > On Fri, Jul 3, 2009 at 11:14 AM, Michael S. Zick wrote: >> Here is one I have found useful in my VIA processor bug hunting: >> >> diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S >> index 3068388..2303d86 100644 >> --- a/arch/x86/kernel/head_32.S >> +++ b/arch/x86/kernel/head_32.S >> @@ -61,7 +61,7 @@ >> >> ?/* Enough space to fit pagetables for the low memory linear map */ >> ?MAPPING_BEYOND_END = \ >> - ? ? ? PAGE_TABLE_SIZE(((1<<32) - __PAGE_OFFSET) >> PAGE_SHIFT) << PAGE_SHIFT >> + ? ? ? PAGE_TABLE_SIZE((1<<20) - (__PAGE_OFFSET >> PAGE_SHIFT)) << PAGE_SHIFT >> >> ?/* >> ?* Worst-case size of the kernel mapping we need to make: >> >> = = = >> >> Before: >> >> ?#5 [0000010000 - 0000011000] ? ? ? ? ?PGTABLE ==> [0000010000 - 0000011000] >> ?#6 [0000011000 - 0000015000] ? ? ? ? ?BOOTMAP ==> [0000011000 - 0000015000] >> >> After: >> >> ?#5 [0000010000 - 000007d000] ? ? ? ? ?PGTABLE ==> [0000010000 - 000007d000] >> ?#6 [000007d000 - 0000081000] ? ? ? ? ?BOOTMAP ==> [000007d000 - 0000081000] >> > > that PGTABLE is from early resource. and it is filled by init_memory_mapping() > > it mean preallocated pgtable to MAPPING_BEYOND_END is small now after > patch. and init_memory_mapping try to get more. > > please send out whole dmesg. with and without your patch. it could > print out initial mapped before e820 allocation is involved for 32bit > ? ? ? ?printk(KERN_DEBUG "initial memory mapped : 0 - %08lx\n", > ? ? ? ? ? ? ? ? ? ? ? ?max_pfn_mapped< > > your patch should be right. except to change that 12 to PAGE_SHIFT > mean >> /* Enough space to fit pagetables for the low memory linear map */ >> MAPPING_BEYOND_END = \ >> - PAGE_TABLE_SIZE(((1<<32) - __PAGE_OFFSET) >> PAGE_SHIFT) << PAGE_SHIFT >> + PAGE_TABLE_SIZE((1<<(32 - PAGE_SHIFT)) - (__PAGE_OFFSET >> PAGE_SHIFT)) << PAGE_SHIFT YH -- 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/