From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754935AbcHSO7d (ORCPT ); Fri, 19 Aug 2016 10:59:33 -0400 Received: from mail-oi0-f43.google.com ([209.85.218.43]:33870 "EHLO mail-oi0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754172AbcHSO7a (ORCPT ); Fri, 19 Aug 2016 10:59:30 -0400 MIME-Version: 1.0 In-Reply-To: <436d7526-bf06-633d-afce-4333552d9e31@linux.intel.com> References: <436d7526-bf06-633d-afce-4333552d9e31@linux.intel.com> From: Dan Williams Date: Fri, 19 Aug 2016 07:59:29 -0700 Message-ID: Subject: Re: DAX can not work on virtual nvdimm device To: Xiao Guangrong Cc: LKML , "linux-nvdimm@lists.01.org" , Linux ACPI , Stefan Hajnoczi , "qemu-devel@nongnu.org" , KVM , "Zhang, Haozhong" , Yumei Huang Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 19, 2016 at 4:19 AM, Xiao Guangrong wrote: > > Hi Dan, > > Recently, Redhat reported that nvml test suite failed on QEMU/KVM, > more detailed info please refer to: > https://bugzilla.redhat.com/show_bug.cgi?id=1365721 > > The reason for this bug is that the memory region created by mmap() > on the dax-based file was gone so that the region can not be found > in /proc/self/smaps during the runtime. > > This is a simple way to trigger this issue: > mount -o dax /dev/pmem0 /mnt/pmem/ > vim /mnt/pmem/xxx > then 'vim' is crashed due to segment fault. > > This bug can be reproduced on your tree, the top commit is > 10d7902fa0e82b (dax: unmap/truncate on device shutdown), the kernel > configure file is attached. > > Your thought or comment is highly appreciated. I'm going to be offline until Tuesday, but I will investigate when I'm back. In the meantime if Ross or Vishal had an opportunity to take a look I wouldn't say "no" :).