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RE: [Xen-users] out of memory with xen

To: "Maarten Vanraes" <maarten@xxxxx>, xen-users@xxxxxxxxxxxxxxxxxxx
Subject: RE: [Xen-users] out of memory with xen
From: "Petersson, Mats" <Mats.Petersson@xxxxxxx>
Date: Wed, 27 Jun 2007 15:56:17 +0200
Cc: Arie Goldfeld <arik.goldfeld@xxxxxxxxx>
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Thread-topic: [Xen-users] out of memory with xen
 

> -----Original Message-----
> From: Maarten Vanraes [mailto:maarten@xxxxx] 
> Sent: 27 June 2007 14:48
> To: xen-users@xxxxxxxxxxxxxxxxxxx
> Cc: Petersson, Mats; Arie Goldfeld
> Subject: Re: [Xen-users] out of memory with xen
> 
> As you can see, this is strictly cache...
> but you could be right, of course, but this is MORE than HALF of the 
> memory!!!.
> 
> Is there a way to get the kernel to try and flush the cache 
> as much as 
> possible (if possible non-destructive?)

Try writing a user-mode program that allocates memory in fair-sized
chunks [also make sure that at least one byte in every page (4K) is
"touched" so that the lazy allocator actually DOES allocate the page -
there's probably another way of forcing this too, but I don't know what
method that is!] - then quickly release the memory at the time when you
start the new domain. 

But I still think using the "dom0_mem=" option is the better solution,
as that guarantees how much memory you can give to DomU's. 

--
Mats
[snip]



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