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From: David Vrabel <david.vrabel@citrix.com>
To: Matt Wilson <msw@linux.com>
Cc: Keir Fraser <keir@xen.org>, Matt Wilson <msw@amazon.com>,
	Matthew Rushton <mvrushton@gmail.com>,
	Andrew Cooper <andrew.cooper3@citrix.com>,
	Tim Deegan <tim@xen.org>, Jan Beulich <jbeulich@suse.com>,
	xen-devel@lists.xenproject.org,
	Malcolm Crossley <malcolm.crossley@citrix.com>
Subject: Re: [RFC PATCH] page_alloc: use first half of higher order chunks when halving
Date: Wed, 26 Mar 2014 10:44:18 +0000	[thread overview]
Message-ID: <5332AF82.2010506@citrix.com> (raw)
In-Reply-To: <20140326101746.GA14195@u109add4315675089e695.ant.amazon.com>

On 26/03/14 10:17, Matt Wilson wrote:
> 
> Konrad, what's the possibility of fixing this in Linux Xen PV setup
> code? I think it'd be a matter batching up pages and doing larger
> order allocations in linux/arch/x86/xen/setup.c:xen_do_chunk(),
> falling back to smaller pages if allocations fail due to
> fragmentation, etc.

We plan to fix problems caused by non-machine-contiguous memory by
setting up the IOMMU to have 1:1 bus to pseudo-physical mappings.  This
would avoid using the swiotlb always[1], regardless of the machine
layout of dom0 or the driver domain.

I think I would prefer this approach rather than making xen/setup.c even
more horribly complicated.

Malcolm has a working prototype of this already.

David

[1] Unless you have a non-64 bit DMA capable device, but we don't care
about performance with these.

  reply	other threads:[~2014-03-26 10:44 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-03-25 11:22 [RFC PATCH] page_alloc: use first half of higher order chunks when halving Matt Wilson
2014-03-25 11:44 ` Andrew Cooper
2014-03-25 13:20   ` Matt Wilson
2014-03-25 20:18     ` Matthew Rushton
2014-03-25 12:19 ` Tim Deegan
2014-03-25 13:27   ` Matt Wilson
2014-03-25 20:09     ` Matthew Rushton
2014-03-26  9:55       ` Tim Deegan
2014-03-26 10:17         ` Matt Wilson
2014-03-26 10:44           ` David Vrabel [this message]
2014-03-26 10:48             ` Matt Wilson
2014-03-26 11:13               ` Ian Campbell
2014-03-26 11:41                 ` Matt Wilson
2014-03-26 11:45                   ` Andrew Cooper
2014-03-26 11:50                     ` Matt Wilson
2014-03-26 12:43               ` David Vrabel
2014-03-26 12:48                 ` Matt Wilson
2014-03-26 15:08           ` Konrad Rzeszutek Wilk
2014-03-26 15:15             ` Matt Wilson
2014-03-26 15:59               ` Matthew Rushton
2014-03-26 16:36                 ` Konrad Rzeszutek Wilk
2014-03-26 17:47                   ` Matthew Rushton
2014-03-26 17:56                     ` Konrad Rzeszutek Wilk
2014-03-26 22:15                       ` Matthew Rushton
2014-03-28 17:02                         ` Konrad Rzeszutek Wilk
2014-03-28 22:06                           ` Matthew Rushton
2014-03-31 14:15                             ` Konrad Rzeszutek Wilk
2014-04-01  3:25                               ` Matthew Rushton
2014-04-01 10:48                                 ` Konrad Rzeszutek Wilk
2014-04-01 12:22                                   ` Tim Deegan
2014-04-02  0:17                                     ` Matthew Rushton
2014-04-02  7:52                                       ` Jan Beulich
2014-04-02 10:06                                         ` Ian Campbell
2014-04-02 10:15                                           ` Jan Beulich
2014-04-02 10:20                                             ` Ian Campbell
2014-04-09 22:21                                               ` Matthew Rushton
2014-04-10  6:14                                                 ` Jan Beulich
2014-04-11 20:20                                                   ` Matthew Rushton
2014-04-11 17:05                                                 ` Konrad Rzeszutek Wilk
2014-04-11 20:28                                                   ` Matthew Rushton
2014-04-12  1:34                                                     ` Konrad Rzeszutek Wilk
2014-04-13 21:32                                                   ` Tim Deegan
2014-04-14  8:51                                                     ` Jan Beulich
2014-04-14 14:40                                                       ` Konrad Rzeszutek Wilk
2014-04-14 15:34                                                         ` Jan Beulich
2014-04-16 14:15                                                           ` Konrad Rzeszutek Wilk
2014-04-17  1:34                                                             ` Matthew Rushton
2014-05-07 23:16                                                             ` Matthew Rushton
2014-05-08 18:05                                                               ` Konrad Rzeszutek Wilk
2014-05-14 15:06                                                               ` Konrad Rzeszutek Wilk
2014-05-20 19:26                                                                 ` Matthew Rushton
2014-05-23 19:00                                                                   ` Konrad Rzeszutek Wilk
2014-06-04 22:25                                                                     ` Matthew Rushton
2014-06-05  9:32                                                                       ` David Vrabel
2014-03-26 16:34               ` Konrad Rzeszutek Wilk

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