Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755907Ab2ENK4L (ORCPT ); Mon, 14 May 2012 06:56:11 -0400 Received: from cantor2.suse.de ([195.135.220.15]:50306 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755368Ab2ENK4J (ORCPT ); Mon, 14 May 2012 06:56:09 -0400 Date: Mon, 14 May 2012 11:56:04 +0100 From: Mel Gorman To: David Miller Cc: akpm@linux-foundation.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, Trond.Myklebust@netapp.com, neilb@suse.de, hch@infradead.org, a.p.zijlstra@chello.nl, michaelc@cs.wisc.edu, emunson@mgebm.net Subject: Re: [PATCH 01/12] netvm: Prevent a stream-specific deadlock Message-ID: <20120514105604.GB29102@suse.de> References: <1336658065-24851-1-git-send-email-mgorman@suse.de> <1336658065-24851-2-git-send-email-mgorman@suse.de> <20120511.011034.557833140906762226.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20120511.011034.557833140906762226.davem@davemloft.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1306 Lines: 33 On Fri, May 11, 2012 at 01:10:34AM -0400, David Miller wrote: > From: Mel Gorman > Date: Thu, 10 May 2012 14:54:14 +0100 > > > It could happen that all !SOCK_MEMALLOC sockets have buffered so > > much data that we're over the global rmem limit. This will prevent > > SOCK_MEMALLOC buffers from receiving data, which will prevent userspace > > from running, which is needed to reduce the buffered data. > > > > Fix this by exempting the SOCK_MEMALLOC sockets from the rmem limit. > > > > Signed-off-by: Peter Zijlstra > > Signed-off-by: Mel Gorman > > This introduces an invariant which I am not so sure is enforced. > > With this change it is absolutely required that once a socket > becomes SOCK_MEMALLOC it must never _ever_ lose that attribute. > This is effectively true. In the NFS case, the flag is cleared on swapoff after all the entries have been paged in. In the NBD case, SOCK_MEMALLOC is left set until the socket is destroyed. I'll update the changelog. -- Mel Gorman SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/