Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Wed, 12 Feb 2020 19:51:59 +0200
From:   Leon Romanovsky <leonro@mellanox.com>
To:     santosh.shilimkar@oracle.com
Cc:     John Hubbard <jhubbard@nvidia.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Hans Westgaard Ry <hans.westgaard.ry@oracle.com>,
        "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, netdev@vger.kernel.org,
        rds-devel@oss.oracle.com, linux-rdma@vger.kernel.org,
        linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/1] net/rds: Track user mapped pages through special API
Message-ID: <20200212175159.GD679970@unreal>
References: <20200212030355.1600749-1-jhubbard@nvidia.com>
 <20200212030355.1600749-2-jhubbard@nvidia.com>
 <c0d8d04e-08d1-60ff-ea4c-e6c71f3e118a@oracle.com>
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <c0d8d04e-08d1-60ff-ea4c-e6c71f3e118a@oracle.com>
MIME-Version: 1.0
Received-SPF: None (protection.outlook.com: mellanox.com does not designate
 permitted sender hosts)
X-MS-Exchange-CrossTenant-Network-Message-Id: 7c3ffc77-241c-45b9-b379-08d7afe44430
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Feb 2020 17:52:02.9790
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: a652971c-7d2e-4d9b-a6a4-d149256f461b
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: L0PjSxxiQSR1wodXQO3OvbOn+/d28d+tC6rbaNKc2y6z/qhDrvKD9xinnEL7s/8RNxT5sWd3K+DvRQgci5SeAw==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM6PR05MB5459
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed, Feb 12, 2020 at 09:31:51AM -0800, santosh.shilimkar@oracle.com wrote:
> On 2/11/20 7:03 PM, John Hubbard wrote:
> > From: Leon Romanovsky <leonro@mellanox.com>
> >
> > Convert net/rds to use the newly introduces pin_user_pages() API,
> > which properly sets FOLL_PIN. Setting FOLL_PIN is now required for
> > code that requires tracking of pinned pages.
> >
> > Note that this effectively changes the code's behavior: it now
> > ultimately calls set_page_dirty_lock(), instead of set_page_dirty().
> > This is probably more accurate.
> >
> > As Christoph Hellwig put it, "set_page_dirty() is only safe if we are
> > dealing with a file backed page where we have reference on the inode it
> > hangs off." [1]
> >
> > [1] https://urldefense.com/v3/__https://lore.kernel.org/r/20190723153640.GB720@lst.de__;!!GqivPVa7Brio!OJHuecs9Iup5ig3kQBi_423uMMuskWhBQAdOICrY3UQ_ZfEaxt9ySY7E8y32Q7pk5tByyA$
> >
> > Cc: Hans Westgaard Ry <hans.westgaard.ry@oracle.com>
> > Cc: Santosh Shilimkar <santosh.shilimkar@oracle.com>
> > Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
> > Signed-off-by: John Hubbard <jhubbard@nvidia.com>
> > ---
> Change looks fine to me. Just on safer side, we will try
> to test this change with regression suite to make sure it
> works as expected.

Thanks Santosh,
I wrote this patch before John's series was merged into the tree,
but back then, Hans tested it and it worked, hope that it still works. :)

>
> For patch itself,
>
> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
>