From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40B2FC07E95 for ; Fri, 16 Jul 2021 15:07:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 22A84613F5 for ; Fri, 16 Jul 2021 15:07:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240496AbhGPPKx (ORCPT ); Fri, 16 Jul 2021 11:10:53 -0400 Received: from outgoing-auth-1.mit.edu ([18.9.28.11]:57661 "EHLO outgoing.mit.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S240493AbhGPPKw (ORCPT ); Fri, 16 Jul 2021 11:10:52 -0400 Received: from callcc.thunk.org (96-65-121-81-static.hfc.comcastbusiness.net [96.65.121.81]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 16GF7fnw014809 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 16 Jul 2021 11:07:42 -0400 Received: by callcc.thunk.org (Postfix, from userid 15806) id D6FEA4202F5; Fri, 16 Jul 2021 11:07:40 -0400 (EDT) Date: Fri, 16 Jul 2021 11:07:40 -0400 From: "Theodore Y. Ts'o" To: Felix Kuehling Cc: Alex Sierra , akpm@linux-foundation.org, linux-mm@kvack.org, rcampbell@nvidia.com, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, hch@lst.de, jgg@nvidia.com, jglisse@redhat.com Subject: Re: [PATCH v3 0/8] Support DEVICE_GENERIC memory in migrate_vma_* Message-ID: References: <20210617151705.15367-1-alex.sierra@amd.com> <905418d1-9099-0ea8-a6e6-84cc8ef3d0b0@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <905418d1-9099-0ea8-a6e6-84cc8ef3d0b0@amd.com> Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Wed, Jun 23, 2021 at 05:49:55PM -0400, Felix Kuehling wrote: > > I can think of two ways to test the changes for MEMORY_DEVICE_GENERIC in > this patch series in a way that is reproducible without special hardware and > firmware: > > For the reference counting changes we could use the dax driver with hmem and > use efi_fake_mem on the kernel command line to create some DEVICE_GENERIC > pages. I'm open to suggestions for good user mode tests to exercise dax > functionality on this type of memory. Sorry for the thread necromancy, but now that the merge window is past.... Today I test ext4's dax support, without having any $$$ DAX hardware, by using the kernel command line "memmap=4G!9G:memmap=9G!14G" which reserves memory so that creates two pmem device and then I run xfstests with DAX enabled using qemu or using a Google Compute Engine VM, using TEST_DEV=/dev/pmem0 and SCRATCH_DEV=/dev/pmem1. If you can give me a recipe for what kernel configs I should enable, and what magic kernel command line arguments to use, then I'd be able to test your patch set with ext4. Cheers, - Ted