From: "Jan Beulich" <JBeulich@novell.com>
To: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Charles Arnold <CARNOLD@novell.com>,
"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
Keir Fraser <keir@xen.org>
Subject: Re: Xen 4.0.1 "xc_map_foreign_batch: mmap failed: Cannot allocate memory"
Date: Wed, 05 Jan 2011 18:10:40 +0000 [thread overview]
Message-ID: <4D24C230020000780002A8D0@vpn.id2.novell.com> (raw)
>>> On 05.01.11 at 18:48, Stefano Stabellini <stefano.stabellini@eu.citrix.com>
wrote:
> On Wed, 5 Jan 2011, Jan Beulich wrote:
>> But this means it can have very close to the total amount of
>> memory the guest has in flight on its own. Clearly this should
>> be throttled based on available memory (just consider you have
>> multiple such I/O hungry guests).
>
> This is true in theory, but Qemu emulates a PIIX3 chipset that only has
> two dma engines so I don't believe is possible to have more than 2 dma
> requests in flight.
> However I am not sure what is the maximum size for a single dma request.
>Oh, no, we're talking about guests using pv drivers (I thought that
>was said in the original mail).
Rubbish. Forget that. Mixed up in my brain with something else.
Jan
next reply other threads:[~2011-01-05 18:10 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-05 18:10 Jan Beulich [this message]
-- strict thread matches above, loose matches on Subject: below --
2011-01-07 9:35 Xen 4.0.1 "xc_map_foreign_batch: mmap failed: Cannot allocate memory" Jan Beulich
2011-01-07 11:18 ` Stefano Stabellini
2011-01-07 12:37 ` Jan Beulich
2011-01-10 11:11 ` Stefano Stabellini
2011-01-07 17:03 ` Charles Arnold
2011-01-06 20:49 Charles Arnold
2010-12-16 19:23 Charles Arnold
2010-12-16 20:33 ` Keir Fraser
2010-12-16 20:44 ` Charles Arnold
2010-12-16 20:54 ` Keir Fraser
2010-12-17 9:22 ` Jan Beulich
2010-12-17 10:06 ` Keir Fraser
2011-01-05 14:37 ` Stefano Stabellini
2011-01-05 15:30 ` Jan Beulich
2011-01-05 16:22 ` Stefano Stabellini
2011-01-05 16:33 ` Jan Beulich
2011-01-05 17:48 ` Stefano Stabellini
2011-01-05 18:09 ` Jan Beulich
2011-01-05 17:17 ` Charles Arnold
2011-01-06 16:50 ` Stefano Stabellini
2011-01-06 17:14 ` Charles Arnold
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