From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <owner-linux-mm@kvack.org>
Date: Tue, 22 May 2018 08:28:06 +0200
From: Christoph Hellwig <hch@lst.de>
To: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>, Christoph Hellwig <hch@lst.de>,
	linux-nvdimm <linux-nvdimm@lists.01.org>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>,
	Michal Hocko <mhocko@suse.com>, kbuild test robot <lkp@intel.com>,
	Thomas Meyer <thomas@m3y3r.de>, Dave Jiang <dave.jiang@intel.com>,
	=?iso-8859-1?B?Suly9G1l?= Glisse <jglisse@redhat.com>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	Linux MM <linux-mm@kvack.org>,
	Gerald Schaefer <gerald.schaefer@de.ibm.com>
Subject: Re: [PATCH v10] mm: introduce MEMORY_DEVICE_FS_DAX and
	CONFIG_DEV_PAGEMAP_OPS
Message-ID: <20180522062806.GD7816@lst.de>
References: <152658753673.26786.16458605771414761966.stgit@dwillia2-desk3.amr.corp.intel.com> <20180518094616.GA25838@lst.de> <CAPcyv4iO1yss0sfBzHVDy3qja_wc+JT2Zi1zwtApDckTeuG2wQ@mail.gmail.com> <20180521090410.7ygosxzjfhceqrq4@quack2.suse.cz>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20180521090410.7ygosxzjfhceqrq4@quack2.suse.cz>
Sender: owner-linux-mm@kvack.org
List-ID: <linux-fsdevel.vger.kernel.org>

On Mon, May 21, 2018 at 11:04:10AM +0200, Jan Kara wrote:
> We definitely do have customers using "execute in place" on s390x from
> dcssblk. I've got about two bug reports for it when customers were updating
> from old kernels using original XIP to kernels using DAX. So we need to
> keep that working.

That is all good an fine, but I think time has come where s390 needs
to migrate to provide the pmem API so that we can get rid of these
special cases.  Especially given that the old XIP/legacy DAX has all
kinds of known bugs at this point in time.