From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751738Ab2LUW0p (ORCPT ); Fri, 21 Dec 2012 17:26:45 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:47708 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751445Ab2LUW0k (ORCPT ); Fri, 21 Dec 2012 17:26:40 -0500 Date: Fri, 21 Dec 2012 17:26:19 -0500 From: Konrad Rzeszutek Wilk To: Yinghai Lu Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "Eric W. Biederman" , linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 12/13] x86, 64bit: Print init kernel lowmap correctly Message-ID: <20121221222619.GA1102@phenom.dumpdata.com> References: <1354089042-10023-1-git-send-email-yinghai@kernel.org> <1354089042-10023-13-git-send-email-yinghai@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1354089042-10023-13-git-send-email-yinghai@kernel.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index 4178530..30f6190 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -304,10 +304,14 @@ void __init init_extra_mapping_uc(unsigned long phys, unsigned long size) > void __init cleanup_highmap(void) > { > unsigned long vaddr = __START_KERNEL_map; > - unsigned long vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT); > + unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE; Should you remove the line in head64.c that sets the max_pfn_mapped to KERNEL_IMAGE_SIZE >> PAGE_SHIFT? > unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1; > pmd_t *pmd = level2_kernel_pgt; > > + /* Xen has its own end somehow with abused max_pfn_mapped */ Could you clarify please? My recollection is that the max_pfn_mapped would point to the end of the RAMdisk. And yes (from mmu.c): 1862 /* max_pfn_mapped is the last pfn mapped in the initial memory 1863 * mappings. Considering that on Xen after the kernel mappings we 1864 * have the mappings of some pages that don't exist in pfn space, we 1865 * set max_pfn_mapped to the last real pfn mapped. */ 1866 max_pfn_mapped = PFN_DOWN(__pa(xen_start_info->mfn_list)); 1867 And if you follow xen_start_info, you get to include/xen/interface/xen.h which has: 406 * 4. This the order of bootstrap elements in the initial virtual region: 407 * a. relocated kernel image 408 * b. initial ram disk [mod_start, mod_len] 409 * c. list of allocated page frames [mfn_list, nr_pages] so per that code I believe max_pfn_mapped covers the kernel and the ramdisk - no more. > + if (max_pfn_mapped) > + vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT); > + > for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) { > if (pmd_none(*pmd)) > continue; > -- This part of the patch does not seem to have much to do with the printk? Should it be seperate patch?