From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jason Gunthorpe <jgg-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Subject: Re: [PATCH 18/22] mm: mark DEVICE_PUBLIC as broken
Date: Thu, 13 Jun 2019 19:44:34 +0000
Message-ID: <20190613194430.GY22062@mellanox.com>
References: <20190613094326.24093-1-hch@lst.de>
 <20190613094326.24093-19-hch@lst.de>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org>
In-Reply-To: <20190613094326.24093-19-hch-jcswGhMUV9g@public.gmane.org>
Content-Language: en-US
Content-ID: <D44695B53F740940B0050C945B58AD6F-wNKe6lTLrGecE4WynfumptQqCkab/8FMAL8bYrjMMd8@public.gmane.org>
List-Unsubscribe: <https://lists.01.org/mailman/options/linux-nvdimm>,
 <mailto:linux-nvdimm-request-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org?subject=unsubscribe>
List-Archive: <http://lists.01.org/pipermail/linux-nvdimm/>
List-Post: <mailto:linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org>
List-Help: <mailto:linux-nvdimm-request-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org?subject=help>
List-Subscribe: <https://lists.01.org/mailman/listinfo/linux-nvdimm>,
 <mailto:linux-nvdimm-request-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org?subject=subscribe>
Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org
Sender: "Linux-nvdimm" <linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org>
To: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Cc: "linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org" <linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org>, "nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org" <nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org>, "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, "dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org" <dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org>, "linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org" <linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org>, =?iso-8859-1?Q?J=E9r=F4me_Glisse?= <jglisse-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Ben Skeggs <bskeggs-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, "linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" <linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
List-Id: dri-devel@lists.freedesktop.org

On Thu, Jun 13, 2019 at 11:43:21AM +0200, Christoph Hellwig wrote:
> The code hasn't been used since it was added to the tree, and doesn't
> appear to actually be usable.  Mark it as BROKEN until either a user
> comes along or we finally give up on it.
> 
> Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
>  mm/Kconfig | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/mm/Kconfig b/mm/Kconfig
> index 0d2ba7e1f43e..406fa45e9ecc 100644
> +++ b/mm/Kconfig
> @@ -721,6 +721,7 @@ config DEVICE_PRIVATE
>  config DEVICE_PUBLIC
>  	bool "Addressable device memory (like GPU memory)"
>  	depends on ARCH_HAS_HMM
> +	depends on BROKEN
>  	select HMM
>  	select DEV_PAGEMAP_OPS

This seems a bit harsh, we do have another kconfig that selects this
one today:

config DRM_NOUVEAU_SVM
        bool "(EXPERIMENTAL) Enable SVM (Shared Virtual Memory) support"
        depends on ARCH_HAS_HMM
        depends on DRM_NOUVEAU
        depends on STAGING
        select HMM_MIRROR
        select DEVICE_PRIVATE
        default n
        help
          Say Y here if you want to enable experimental support for
          Shared Virtual Memory (SVM).

Maybe it should be depends on STAGING not broken?

or maybe nouveau_svm doesn't actually need DEVICE_PRIVATE?

Jason