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Date:   Sun, 17 May 2020 12:38:06 -0700 (PDT)
Message-Id: <20200517.123806.1659008654334663086.davem@davemloft.net>
To:     jhubbard@nvidia.com
Cc:     linux-kernel@vger.kernel.org, kuba@kernel.org,
        netdev@vger.kernel.org, linux-rdma@vger.kernel.org,
        rds-devel@oss.oracle.com
Subject: Re: [PATCH] rds: convert get_user_pages() --> pin_user_pages()
From:   David Miller <davem@davemloft.net>
In-Reply-To: <20200517012336.382624-1-jhubbard@nvidia.com>
References: <20200517012336.382624-1-jhubbard@nvidia.com>
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From: John Hubbard <jhubbard@nvidia.com>
Date: Sat, 16 May 2020 18:23:36 -0700

> This code was using get_user_pages_fast(), in a "Case 2" scenario
> (DMA/RDMA), using the categorization from [1]. That means that it's
> time to convert the get_user_pages_fast() + put_page() calls to
> pin_user_pages_fast() + unpin_user_pages() calls.
> 
> There is some helpful background in [2]: basically, this is a small
> part of fixing a long-standing disconnect between pinning pages, and
> file systems' use of those pages.
> 
> [1] Documentation/core-api/pin_user_pages.rst
> 
> [2] "Explicit pinning of user-space pages":
>     https://lwn.net/Articles/807108/
> 
> Cc: David S. Miller <davem@davemloft.net>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: netdev@vger.kernel.org
> Cc: linux-rdma@vger.kernel.org
> Cc: rds-devel@oss.oracle.com
> Signed-off-by: John Hubbard <jhubbard@nvidia.com>

Applied to net-next, thanks.