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Date: Thu, 23 Oct 2008 09:25:12 -0500
From: Anthony Liguori <aliguori@us.ibm.com>
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Subject: [Qemu-devel] Re: [PATCH 01/32] use anonymous memory for kqemu.
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To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Glauber Costa <glommer@redhat.com>, jes@sgi.com, qemu-devel@nongnu.org, avi@qumranet.com, dmitry.baryshkov@siemens.com

Jan Kiszka wrote:
> Anthony Liguori wrote:
>   
>> The idea behind this patch is that currently kqemu uses /dev/shm for
>> memory allocations instead of anonymous memory (like the rest of QEMU). 
>> Instead of introducing YA hook, we can just switch kqemu to use
>> anonymous memory and eliminate the special case.
>>
>> If I recall correctly, the reason for using /dev/shm was concern that
>> get_user_pages() didn't do the right thing for anonymous memory and the
>> use of /dev/shm was a hack around that.  However, I'm not sure that was
>> ever the case.  Certainly, with any sufficiently modern kernel
>> get_user_pages() does what one would expect.  KVM uses get_user_pages()
>> on anonymous memory in roughly the same way kqemu uses it now.
>>
>> So I think it's safe to make the switch.  Fabrice, what do you think?
>>     
>
> This hack-around, was it purely Linux-motivated? Or did/do other OSes
> have similar issues?
>   

/dev/shm doesn't exist on anything but Linux.

Regards,

Anthony Liguori

> Jan
>
>