From: Keir Fraser <keir@xen.org>
To: Jan Beulich <JBeulich@novell.com>, Olaf Hering <olaf@aepfle.de>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>
Subject: Re: Re: non-contiguous allocations
Date: Mon, 09 May 2011 09:34:37 +0100 [thread overview]
Message-ID: <C9ED65AD.2D164%keir@xen.org> (raw)
In-Reply-To: <4DC7C2400200007800040539@vpn.id2.novell.com>
On 09/05/2011 09:30, "Jan Beulich" <JBeulich@novell.com> wrote:
>> Yes, sticking with alloc_xenheap_pages() is good.
>
> It really depends on whether you expect to get memory that has
> (even on 32-bit) a virtual mapping, or you want to map it at an
> arbitrary virtual address after wards. alloc_xenheap_pages() gives
> you mapped memory (and the amount you can get is rather limited
> on 32-bit), while alloc_domheap_pages(NULL, ...) gives you
> memory that has a mapping only on 64-bit (and, once we'll find it
> necessary to support machines with more than 5Tb, even that
> may not hold anymore) but it equally not associated with any
> domain.
We have a mechanism for sharing xenheap pages with a guest, which xentrace
is already using. Doing the same with anonymous domheap pages would be extra
hassle. The limitation of xenheap on x86_32 is uninteresting to me,
especially when we're talking about a niche developer feature like xentrace.
-- Keir
next prev parent reply other threads:[~2011-05-09 8:34 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-30 18:04 [PATCH 0 of 3] xentrace updates Olaf Hering
2011-03-30 18:04 ` [PATCH 1 of 3] xentrace: correct formula to calculate t_info_pages Olaf Hering
2011-04-01 10:32 ` George Dunlap
2011-03-30 18:04 ` [PATCH 2 of 3] xentrace: use tbuf_size for overflow check Olaf Hering
2011-04-01 11:18 ` George Dunlap
2011-04-05 10:19 ` Olaf Hering
2011-04-07 13:50 ` Olaf Hering
2011-04-18 18:45 ` non-contiguous allocations Olaf Hering
2011-04-26 11:51 ` Jan Beulich
2011-05-06 10:25 ` Olaf Hering
2011-05-06 10:45 ` Jan Beulich
2011-05-06 18:12 ` Olaf Hering
2011-05-06 18:46 ` Keir Fraser
2011-05-07 8:39 ` Olaf Hering
2011-05-07 16:31 ` Keir Fraser
2011-05-09 8:30 ` Jan Beulich
2011-05-09 8:34 ` Keir Fraser [this message]
2011-05-09 12:43 ` Olaf Hering
2011-05-09 14:14 ` Keir Fraser
2011-03-30 18:04 ` [PATCH 3 of 3] xentrace: remove unneeded debug printk Olaf Hering
2011-04-01 11:18 ` George Dunlap
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