Re: [PATCH v4 3/3] net/xdp: convert put_page() to put_user_page*()

From: "Björn Töpel" <bjorn.topel@intel.com>
To: john.hubbard@gmail.com, Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
	Christian Benvenuti <benve@cisco.com>,
	Christoph Hellwig <hch@infradead.org>,
	Dan Williams <dan.j.williams@intel.com>,
	"Darrick J . Wong" <darrick.wong@oracle.com>,
	Dave Chinner <david@fromorbit.com>,
	Ira Weiny <ira.weiny@intel.com>, Jan Kara <jack@suse.cz>,
	Jason Gunthorpe <jgg@ziepe.ca>, Jens Axboe <axboe@kernel.dk>,
	Jerome Glisse <jglisse@redhat.com>,
	"Kirill A . Shutemov" <kirill@shutemov.name>,
	Matthew Wilcox <willy@infradead.org>,
	Michal Hocko <mhocko@kernel.org>,
	Mike Marciniszyn <mike.marciniszyn@intel.com>,
	Mike Rapoport <rppt@linux.ibm.com>,
	linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-mm@kvack.org, linux-xfs@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>,
	John Hubbard <jhubbard@nvidia.com>,
	Magnus Karlsson <magnus.karlsson@intel.com>,
	"David S . Miller" <davem@davemloft.net>,
	netdev@vger.kernel.org
Subject: Re: [PATCH v4 3/3] net/xdp: convert put_page() to put_user_page*()
Date: Wed, 31 Jul 2019 08:08:59 +0200	[thread overview]
Message-ID: <c1c7b6cd-8f08-0e3f-2f66-557228edabcf@intel.com> (raw)
In-Reply-To: <20190730205705.9018-4-jhubbard@nvidia.com>

On 2019-07-30 22:57, john.hubbard@gmail.com wrote:
> From: John Hubbard <jhubbard@nvidia.com>
> 
> For pages that were retained via get_user_pages*(), release those pages
> via the new put_user_page*() routines, instead of via put_page() or
> release_pages().
> 
> This is part a tree-wide conversion, as described in commit fc1d8e7cca2d
> ("mm: introduce put_user_page*(), placeholder versions").
> 
> Cc: Björn Töpel <bjorn.topel@intel.com>
> Cc: Magnus Karlsson <magnus.karlsson@intel.com>
> Cc: David S. Miller <davem@davemloft.net>
> Cc: netdev@vger.kernel.org
> Signed-off-by: John Hubbard <jhubbard@nvidia.com>

Acked-by: Björn Töpel <bjorn.topel@intel.com>

> ---
>   net/xdp/xdp_umem.c | 9 +--------
>   1 file changed, 1 insertion(+), 8 deletions(-)
> 
> diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
> index 83de74ca729a..17c4b3d3dc34 100644
> --- a/net/xdp/xdp_umem.c
> +++ b/net/xdp/xdp_umem.c
> @@ -166,14 +166,7 @@ void xdp_umem_clear_dev(struct xdp_umem *umem)
>   
>   static void xdp_umem_unpin_pages(struct xdp_umem *umem)
>   {
> -	unsigned int i;
> -
> -	for (i = 0; i < umem->npgs; i++) {
> -		struct page *page = umem->pgs[i];
> -
> -		set_page_dirty_lock(page);
> -		put_page(page);
> -	}
> +	put_user_pages_dirty_lock(umem->pgs, umem->npgs, true);
>   
>   	kfree(umem->pgs);
>   	umem->pgs = NULL;
>