From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from e06smtp12.uk.ibm.com ([195.75.94.108]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Uyj5b-0004py-28 for kexec@lists.infradead.org; Mon, 15 Jul 2013 13:45:19 +0000 Received: from /spool/local by e06smtp12.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 15 Jul 2013 14:39:33 +0100 Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by d06dlp01.portsmouth.uk.ibm.com (Postfix) with ESMTP id C9CB817D801A for ; Mon, 15 Jul 2013 14:46:30 +0100 (BST) Received: from d06av08.portsmouth.uk.ibm.com (d06av08.portsmouth.uk.ibm.com [9.149.37.249]) by b06cxnps4074.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r6FDigXB22413360 for ; Mon, 15 Jul 2013 13:44:42 GMT Received: from d06av08.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av08.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id r6FDirVX031168 for ; Mon, 15 Jul 2013 07:44:53 -0600 Date: Mon, 15 Jul 2013 15:44:51 +0200 From: Michael Holzheu Subject: Re: [PATCH v6 3/5] vmcore: Introduce remap_oldmem_pfn_range() Message-ID: <20130715154451.02a3a767@holzheu> In-Reply-To: <20130702154214.GC22603@redhat.com> References: <1372707159-10425-1-git-send-email-holzheu@linux.vnet.ibm.com> <1372707159-10425-4-git-send-email-holzheu@linux.vnet.ibm.com> <20130702154214.GC22603@redhat.com> Mime-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=twosheds.infradead.org@lists.infradead.org To: Vivek Goyal , Andrew Morton Cc: Heiko Carstens , kexec@lists.infradead.org, Jan Willeke , linux-kernel@vger.kernel.org, HATAYAMA Daisuke , Martin Schwidefsky On Tue, 2 Jul 2013 11:42:14 -0400 Vivek Goyal wrote: > On Mon, Jul 01, 2013 at 09:32:37PM +0200, Michael Holzheu wrote: > > For zfcpdump we can't map the HSA storage because it is only available > > via a read interface. Therefore, for the new vmcore mmap feature we have > > introduce a new mechanism to create mappings on demand. > > > > This patch introduces a new architecture function remap_oldmem_pfn_range() > > that should be used to create mappings with remap_pfn_range() for oldmem > > areas that can be directly mapped. For zfcpdump this is everything besides > > of the HSA memory. For the areas that are not mapped by remap_oldmem_pfn_range() > > a generic vmcore a new generic vmcore fault handler mmap_vmcore_fault() > > is called. > > > > This handler works as follows: > > > > * Get already available or new page from page cache (find_or_create_page) > > * Check if /proc/vmcore page is filled with data (PageUptodate) > > * If yes: > > Return that page > > * If no: > > Fill page using __vmcore_read(), set PageUptodate, and return page > > > > Signed-off-by: Michael Holzheu > > In general vmcore related changes look fine to me. I am not very familiar > with the logic of finding pages in page cache and using page uptodate > flag. > > Hatayama, can you please review it. > > Acked-by: Vivek Goyal Hello Vivek and Andrew, We just realized that Hatayama's mmap patches went into v3.11-rc1. This currently breaks s390 kdump because of the following two issues: 1) The copy_oldmem_page() is now used for copying to vmalloc memory 2) The mmap() implementation is not compatible with the current s390 crashkernel swap: See: http://marc.info/?l=kexec&m=136940802511603&w=2 The "kdump: Introduce ELF header in new memory feature" patch series will fix both issues for s390. There is the one small open discussion left: http://www.mail-archive.com/linux-kernel@vger.kernel.org/msg464856.html But once we have finished that, would it be possible to get the patches in 3.11? Michael _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec