From: Jiri Slaby Subject: Re: [RFC 1/1] mm: add virt to phys debug Date: Tue, 13 May 2008 16:38:51 +0200 Message-ID: <4829A7FB.5070507@gmail.com> References: <1209669740-10493-1-git-send-email-jirislaby@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-mm@kvack.org, Ingo Molnar , "H. Peter Anvin" , Jeremy Fitzhardinge , pageexec@freemail.hu, Mathieu Desnoyers , herbert@gondor.apana.org.au, penberg@cs.helsinki.fi, akpm@linux-foundation.org, linux-ext4@vger.kernel.org, paulmck@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, Andi Kleen To: Christoph Lameter Return-path: Received: from wx-out-0506.google.com ([66.249.82.231]:39893 "EHLO wx-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757607AbYEMOi6 (ORCPT ); Tue, 13 May 2008 10:38:58 -0400 Received: by wx-out-0506.google.com with SMTP id h29so2297014wxd.4 for ; Tue, 13 May 2008 07:38:57 -0700 (PDT) In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: Christoph Lameter napsal(a): > On Thu, 1 May 2008, Jiri Slaby wrote: >> Add some (configurable) expensive sanity checking to catch wrong address >> translations on x86. >> >> - create linux/mmdebug.h file to be able include this file in >> asm headers to not get unsolvable loops in header files >> - __phys_addr on x86_32 became a function in ioremap.c since >> PAGE_OFFSET and is_vmalloc_addr is undefined if declared in >> page_32.h (again circular dependencies) >> - add __phys_addr_const for initializing doublefault_tss.__cr3 > > Hmmm.. We could use include/linux/bounds.h to make > VMALLOC_START/VMALLOC_END (or whatever you need for checking the memory > boundaries) a cpp constant which may allow the use in page_32.h without > circular dependencies. Hrm, not that easy. I ended up in splitting fixmap_32.h (VMALLOC constants depends on it on 32-bit), moving around constants from over all the tree (NR_CPUS, FIX_ACPI_PAGES...) to not include files which would create loops, but still not having e.g. PMD_MASK available on all configurations. I think it's not worth it. Objections to merging the patch as was (http://lkml.org/lkml/2008/5/1/300)? Thanks.