Re: In kvm, a single process cannot allocate more than 3.6GB ram. Why?

[Avi Kivity <avi@redhat.com>]

On 12/12/2009 11:23 AM, Tanel Kokk wrote:
> On 12/12/09 10:55, Avi Kivity wrote:
>    
>> On 12/11/2009 11:03 AM, Tanel Kokk wrote:
>>      
>>> Does anybody have a glue why process are not able to allocate more than
>>> 3.6GB memory ?
>>>
>>> What should i do to allow process allocate more than 3.6GB memory? Is it
>>> possible at all?
>>>
>>>        
>> A guest or host process?  And what happens when you try?
>>      
> guest process
>
> We discovered that if postgres process (on guest) used to use only 3.6GB
> memory regardless of guest had 8GB memory in common.
>
>    


That's probably a postgres configuration error (or you're using 32-bit 
postgres).


> Then I made simple python script, which just eat memory:
> ------------------------------------
> #!/usr/bin/python
> import time, random
>
> i = 0
> while (i<  100000000):
>      a[i] = random.random()
>      i = i + 1
>
> time.sleep(600)
> ------------------------------------
> And I get python MemoryError, when script has devoured about 3.6GB ram
>    


Doesn't mean much - Python may allocate a lot more memory when extending 
the array.

What does 'cat /proc/meminfo' in the guest say?

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.