[Starlingx-discuss] Question - Using 1Gb mem pages

[Michel Thebeau]

Hi Ricardo,

The documentation indicates to configure the the huge pages per numa 
node on the compute, and to configure the flavour extra specs for the 
VM.  I am not aware of anything else in particular. There's some tips 
and caveats in the document, but I don't see anything in your message to 
think of those.

If there's any chance you are trying to do this under virtualization, I 
am not aware that that is currently supported.

M


On 2018-10-19 6:14 p.m., Perez, Ricardo O wrote:
> Hi Michael,
>
> Thanks for your answer, I just forgot to put the computes information about memory configuration, here is the info:
>
> Compute-0
>
>     VM Pages
> 0   Reserved for Platform: 8000 MiB
> Usable Total: 86387 MiB
> Available: 84787 MiB
>      4K Pages:
>      Total: 230656
> 2M Hugepages:
>      Total: 1271
>      Available: 983
> 1G Hugepages:
>      Total: 80
>      Available: 80
>
> 1   Reserved for Platform: 2000 MiB
> Usable Total: 93698 MiB
> Available: 92674 MiB
>      4K Pages:
>      Total: 29696
> 2M Hugepages:
>      Total: 5319
>      Available: 5319
> 1G Hugepages:
>      Total: 80
>      Available: 80
>
> ***********************************
> Compute-1
> Processor
>      Memory
>      VM Pages
> 0   Reserved for Platform: 8000 MiB
> Usable Total: 86504 MiB
> Available: 84968 MiB
>      4K Pages:
>      Total: 0
> 2M Hugepages:
>      Total: 1780
>      Available: 1524
> 1G Hugepages:
>      Total: 80
>      Available: 80
>
> 1   Reserved for Platform: 2000 MiB
> Usable Total: 93552 MiB
> Available: 92528 MiB
>      4K Pages:
>      Total: 0
> 2M Hugepages:
>      Total: 5304
>      Available: 5304
> 1G Hugepages:
>      Total: 80
>      Available: 80
>
> Am I missing something else to made use of 1G memory pages ?
>
> Thanks
> -Richo
>
>> -----Original Message-----
>> From: Michel Thebeau [mailto:michel.thebeau at windriver.com]
>> Sent: Friday, October 19, 2018 1:39 PM
>> To: Perez, Ricardo O <ricardo.o.perez at intel.com>; starlingx-
>> discuss at lists.starlingx.io
>> Subject: Re: [Starlingx-discuss] Question - Using 1Gb mem pages
>>
>> On 2018-10-19 1:45 p.m., Perez, Ricardo O wrote:
>>> Hello,
>>>
>>> I'm trying to execute a test, which his goal is to made use of huge pages (2M /
>> 1G) launching a VM.
>>> I have already verified the configuration of the controllers GRUB options and
>> we have defined the variable hugepagesz=1G, however, inside the same
>> parameters list, there is a "default_hugepagesz=2M". The default hugepagesz,
>> has been modified to 1G, and the compute has been restarted with no issues.
>>
>>
>> Hi Ricardo,
>>
>> You wrote, "controllers GRUB options" then "the compute has been restarted
>> with no issues".  Is there a GRUB option one can configure on the controller that
>> is for the computes?  I don't remember seeing one. If you're actually changing
>> /etc/default/grub, I doubt that's supported.
>> I did not find a procedure for changing default_hugepagesz  on controllers or
>> computes grub configuration.
>>
>> It's supposed to be an option, for example through in horizon interface or
>> 'system host-memory-modify'... but you didn't quote either of those.
>>
>>
>>> The flavor has been modified, with the following option: "
>> hw:mem_page_size=104875"  (1G) page.
>>
>>
>> Is "104875" a typo?  It looks a lot like 1024 * 1024 = 1048576, but not
>> quite.
>>
>>
>> M
>>
>>
>>> However when I launch a VM using the modified flavor it creates the VM, but if
>> I check the field values of the VM using " openstack server show <vm_name>".
>> I'm getting the following value for pgsize:
>>> wrs-res:topology                    | node:0,   512MB, pgsize:2M, vcpus:0, pol:sha |
>>>
>>> So, seems like it's still taking the 2M pagesize instead of the 1G.
>>>
>>> What I have already tried is to:
>>>
>>> *        Change also the image metadata: hw:mem_page_size=large and also
>> 104875. Result, VM launched successfully, but pgsize value still 2M.
>>
>> There's the interesting "104875" again.
>>
>>
>>> *        Leave the GRUB default values, and use modified flavor to
>> hw:mem_page_size=104875, launch the VM with ERROR status.
>>
>> 104875
>>
>>> *        Leave the GRUB default values, and use modified flavor to
>> hw:mem_page_size=2048, launch the VM with success, , pgsize value is 2M,
>> which is expected, ok.
>>> *        Leave the GRUB default values, and use modified flavor to
>> hw:mem_page_size=small launch the VM with success, , pgsize value is 4k,
>> which is  expected, ok.
>>> *        Leave the GRUB default values, and use modified flavor to
>> hw:mem_page_size=any launch the VM with success, , pgsize value is 2M, which
>> is  expected, ok.
>>> Could be this an issue trying to use 1G mem pages or do I'm missing some
>> other configuration parameter?
>>> Thanks in advance for your help
>>>
>>>
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