From: Mel Gorman <mgorman@suse.de>
To: Christoph Hellwig <hch@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Linux-MM <linux-mm@kvack.org>,
Linux-Netdev <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
David Miller <davem@davemloft.net>, Neil Brown <neilb@suse.de>,
Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [PATCH 00/14] Swap-over-NBD without deadlocking v5
Date: Fri, 15 Jul 2011 15:10:21 +0100 [thread overview]
Message-ID: <20110715141021.GZ7529@suse.de> (raw)
In-Reply-To: <20110707125831.GA15412@infradead.org>
On Thu, Jul 07, 2011 at 08:58:31AM -0400, Christoph Hellwig wrote:
> On Thu, Jul 07, 2011 at 10:47:37AM +0100, Mel Gorman wrote:
> > Additional complexity is required for swap-over-NFS but affects the
> > core kernel far less than this series. I do not have a series prepared
> > but from what's in a distro kernel, supporting NFS requires extending
> > address_space_operations for swapfile activation/deactivation with
> > some minor helpers and the bulk of the remaining complexity within
> > NFS itself.
>
> The biggest addition for swap over NFS is to add proper support for
> a filesystem interface to do I/O on random kernel pages instead of
> the current nasty bmap hack the swapfile code is using. Splitting
> that work from all the required VM infrastructure should make life
> easier for everyone involved and allows merging it independeny as
> both bits have other uses case as well.
>
The swap-over-nfs patches allows this possibility. There is a swapon
interface added that could be used by the filesystem to ensure the
underlying blocks are allocated and a swap_out/swap_in interface that
takes a struct file, struct page and writeback_control. This would
be an alternative to bmap being used to record the blocks backing
each extent.
Any objection to the swap-over-NBD stuff going ahead to get part of the
complexity out of the way?
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2011-07-15 14:10 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-20 13:12 [PATCH 00/14] Swap-over-NBD without deadlocking v5 Mel Gorman
2011-06-20 13:12 ` [PATCH 01/14] mm: Serialize access to min_free_kbytes Mel Gorman
2011-07-06 23:44 ` Andrew Morton
2011-07-07 9:17 ` Mel Gorman
2011-06-20 13:12 ` [PATCH 02/14] mm: sl[au]b: Add knowledge of PFMEMALLOC reserve pages Mel Gorman
2011-06-20 13:12 ` [PATCH 03/14] mm: Introduce __GFP_MEMALLOC to allow access to emergency reserves Mel Gorman
2011-06-20 13:12 ` [PATCH 04/14] mm: allow PF_MEMALLOC from softirq context Mel Gorman
2011-06-20 13:12 ` [PATCH 05/14] mm: Ignore mempolicies when using ALLOC_NO_WATERMARK Mel Gorman
2011-06-20 13:12 ` [PATCH 06/14] net: Introduce sk_allocation() to allow addition of GFP flags depending on the individual socket Mel Gorman
2011-06-20 13:12 ` [PATCH 07/14] netvm: Allow the use of __GFP_MEMALLOC by specific sockets Mel Gorman
2011-06-20 13:12 ` [PATCH 08/14] netvm: Allow skb allocation to use PFMEMALLOC reserves Mel Gorman
2011-06-20 13:12 ` [PATCH 09/14] netvm: Propagate page->pfmemalloc to skb Mel Gorman
2011-06-20 13:12 ` [PATCH 10/14] netvm: Set PF_MEMALLOC as appropriate during SKB processing Mel Gorman
2011-06-20 13:12 ` [PATCH 11/14] mm: Micro-optimise slab to avoid a function call Mel Gorman
2011-06-20 13:12 ` [PATCH 12/14] nbd: Set SOCK_MEMALLOC for access to PFMEMALLOC reserves Mel Gorman
2011-06-20 13:12 ` [PATCH 13/14] mm: Throttle direct reclaimers if PF_MEMALLOC reserves are low and swap is backed by network storage Mel Gorman
2011-06-20 13:12 ` [PATCH 14/14] mm: Account for the number of times direct reclaimers get throttled Mel Gorman
2011-07-06 23:51 ` [PATCH 00/14] Swap-over-NBD without deadlocking v5 Andrew Morton
2011-07-07 9:47 ` Mel Gorman
2011-07-07 12:58 ` Christoph Hellwig
2011-07-15 14:10 ` Mel Gorman [this message]
2011-07-15 15:27 ` Christoph Hellwig
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