From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx147.postini.com [74.125.245.147]) by kanga.kvack.org (Postfix) with SMTP id 9D7B96B0032 for ; Thu, 6 Jun 2013 21:02:30 -0400 (EDT) Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id AF2563EE0C7 for ; Fri, 7 Jun 2013 10:02:28 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 9D56645DE54 for ; Fri, 7 Jun 2013 10:02:28 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 6481745DE53 for ; Fri, 7 Jun 2013 10:02:28 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 34817E18008 for ; Fri, 7 Jun 2013 10:02:28 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.240.81.134]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 401351DB803E for ; Fri, 7 Jun 2013 10:02:27 +0900 (JST) Message-ID: <51B130F9.8070408@jp.fujitsu.com> Date: Fri, 07 Jun 2013 10:01:45 +0900 From: HATAYAMA Daisuke MIME-Version: 1.0 Subject: Re: [PATCH v8 9/9] vmcore: support mmap() on /proc/vmcore References: <20130523052421.13864.83978.stgit@localhost6.localdomain6> <20130523052547.13864.83306.stgit@localhost6.localdomain6> <10307835.fkACLi6FUD@wuerfel> In-Reply-To: <10307835.fkACLi6FUD@wuerfel> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Arnd Bergmann Cc: vgoyal@redhat.com, ebiederm@xmission.com, akpm@linux-foundation.org, cpw@sgi.com, kumagai-atsushi@mxc.nes.nec.co.jp, lisa.mitchell@hp.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, zhangyanfei@cn.fujitsu.com, jingbai.ma@hp.com, linux-mm@kvack.org, riel@redhat.com, walken@google.com, hughd@google.com, kosaki.motohiro@jp.fujitsu.com (2013/06/07 6:31), Arnd Bergmann wrote: > On Thursday 23 May 2013 14:25:48 HATAYAMA Daisuke wrote: >> This patch introduces mmap_vmcore(). >> >> Don't permit writable nor executable mapping even with mprotect() >> because this mmap() is aimed at reading crash dump memory. >> Non-writable mapping is also requirement of remap_pfn_range() when >> mapping linear pages on non-consecutive physical pages; see >> is_cow_mapping(). >> >> Set VM_MIXEDMAP flag to remap memory by remap_pfn_range and by >> remap_vmalloc_range_pertial at the same time for a single >> vma. do_munmap() can correctly clean partially remapped vma with two >> functions in abnormal case. See zap_pte_range(), vm_normal_page() and >> their comments for details. >> >> On x86-32 PAE kernels, mmap() supports at most 16TB memory only. This >> limitation comes from the fact that the third argument of >> remap_pfn_range(), pfn, is of 32-bit length on x86-32: unsigned long. >> >> Signed-off-by: HATAYAMA Daisuke >> Acked-by: Vivek Goyal > > I get build errors on 'make randconfig' from this, when building > NOMMU kernels on ARM. I suppose the new feature should be hidden > in #ifdef CONFIG_MMU. > > Arnd > Thanks for trying the build and your report! OTOH, I don't have no-MMU architectures; x86 box only. I cannot reproduce this build error. Could you give me your build log? I want to use it to detect what part depends on CONFIG_MMU. -- Thanks. HATAYAMA, Daisuke -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org