Message-ID: <4FE20B9C.7010209@redhat.com>
Date: Wed, 20 Jun 2012 13:42:52 -0400
From: Rik van Riel <riel@redhat.com>
MIME-Version: 1.0
To: Mel Gorman <mgorman@suse.de>
CC: Andrew Morton <akpm@linux-foundation.org>, Linux-MM <linux-mm@kvack.org>,
        Linux-Netdev <netdev@vger.kernel.org>,
        Linux-NFS <linux-nfs@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        David Miller <davem@davemloft.net>,
        Trond Myklebust <Trond.Myklebust@netapp.com>,
        Neil Brown <neilb@suse.de>, Christoph Hellwig <hch@infradead.org>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Mike Christie <michaelc@cs.wisc.edu>,
        Eric B Munson <emunson@mgebm.net>
Subject: Re: [PATCH 11/12] nfs: Prevent page allocator recursions with swap
 over NFS.
References: <1340185081-22525-1-git-send-email-mgorman@suse.de> <1340185081-22525-12-git-send-email-mgorman@suse.de>
In-Reply-To: <1340185081-22525-12-git-send-email-mgorman@suse.de>
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Sender: linux-nfs-owner@vger.kernel.org

On 06/20/2012 05:38 AM, Mel Gorman wrote:
> GFP_NOFS is _more_ permissive than GFP_NOIO in that it will initiate
> IO, just not of any filesystem data.
>
> The problem is that previously NOFS was correct because that avoids
> recursion into the NFS code. With swap-over-NFS, it is no longer
> correct as swap IO can lead to this recursion.
>
> Signed-off-by: Peter Zijlstra<a.p.zijlstra@chello.nl>
> Signed-off-by: Mel Gorman<mgorman@suse.de>

Acked-by: Rik van Riel<riel@redhat.com>