Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758126AbXJaK47 (ORCPT ); Wed, 31 Oct 2007 06:56:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753607AbXJaK4v (ORCPT ); Wed, 31 Oct 2007 06:56:51 -0400 Received: from viefep20-int.chello.at ([62.179.121.40]:47084 "EHLO viefep20-int.chello.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753591AbXJaK4u (ORCPT ); Wed, 31 Oct 2007 06:56:50 -0400 Subject: Re: [PATCH 00/33] Swap over NFS -v14 From: Peter Zijlstra To: Christoph Hellwig Cc: David Miller , nickpiggin@yahoo.com.au, torvalds@linux-foundation.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, trond.myklebust@fys.uio.no In-Reply-To: <20071031085041.GA4362@infradead.org> References: <20071030160401.296770000@chello.nl> <200710311426.33223.nickpiggin@yahoo.com.au> <20071030.213753.126064697.davem@davemloft.net> <20071031085041.GA4362@infradead.org> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-cUHl4ABf0oLSQQRRgXos" Date: Wed, 31 Oct 2007 11:56:46 +0100 Message-Id: <1193828206.27652.145.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2325 Lines: 65 --=-cUHl4ABf0oLSQQRRgXos Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Wed, 2007-10-31 at 08:50 +0000, Christoph Hellwig wrote: > On Tue, Oct 30, 2007 at 09:37:53PM -0700, David Miller wrote: > > Don't be misled. Swapping over NFS is just a scarecrow for the > > seemingly real impetus behind these changes which is network storage > > stuff like iSCSI. >=20 > So can we please do swap over network storage only first? All these > VM bits look conceptually sane to me, while the changes to the swap > code to support nfs are real crackpipe material. Yeah, I know how you stand on that. I just wanted to post all this before going off into the woods reworking it all. > Then again doing > that part properly by adding address_space methods for swap I/O without > the abuse might be a really good idea, especially as the way we > do swapfiles on block-based filesystems is an horrible hack already. Is planned. What do you think of the proposed a_ops extension to accomplish this? That is, ->swapfile() - is this address space willing to back swap ->swapout() - write out a page ->swapin() - read in a page > So please get the VM bits for swap over network blockdevices in first, Trouble with that part is that we don't have any sane network block devices atm, NBD is utter crap, and iSCSI is too complex to be called sane. Maybe Evgeniy's Distributed storage thingy would work, will have a look at that. > and then we can look into a complete revamp of the swapfile support > that cleans up the current mess and adds support for nfs insted of > making the mess even worse. Sure, concrete suggestion are always welcome. Just being told something is utter crap only goes so far. --=-cUHl4ABf0oLSQQRRgXos Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQBHKF9uXA2jU0ANEf4RAieaAKCGdTzP/wHrCLDUDz9z475A0L5bVQCbBcEK 4yhY/VPt+xfs+DU4yvLpMS8= =9lsn -----END PGP SIGNATURE----- --=-cUHl4ABf0oLSQQRRgXos-- - 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/