[Mavrick] SRU v2: Set maximum of domain visible memory to 70G

Tim Gardner tim.gardner at canonical.com
Fri Dec 10 16:28:31 GMT 2010


On 12/10/2010 08:52 AM, Stefan Bader wrote:
> On 12/10/2010 04:02 PM, Stefan Bader wrote:
>> On 12/10/2010 03:52 PM, Tim Gardner wrote:
>>> On 12/10/2010 07:10 AM, Stefan Bader wrote:
>>>> SRU justification:
>>>>
>>>> Impact: The config option XEN_MAX_DOMAIN_MEMORY controls how much memory
>>>> a Xen instance is seeing. The default for 64bit is 32GB, which is the
>>>> reason that m2.4xlarge instances only report this amount of memory.
>>>>
>>>> Fix: Setting this limit to 70GB as there is a known restriction for
>>>> t1.micro instances at about 80GB.
>>>>
>>>> Testcase: Booted m2.4xlarge with this set to 32GB shows 32GB of memory,
>>>> when set to 70GB, it correctly reports 68GB. Booted a t1.micro as well
>>>> to verify this has not caused problems there.
>>>>
>>>>   From c72705539ee164cdd100570c1340887f81a63d98 Mon Sep 17 00:00:00 2001
>>>> From: Stefan Bader<stefan.bader at canonical.com>
>>>> Date: Thu, 9 Dec 2010 17:59:36 +0100
>>>> Subject: [PATCH] UBUNTU: Set maximum of domain visible memory to 70G
>>>>
>>>> BugLink: http://bugs.launchpad.net/bugs/667796
>>>>
>>>> Otherwise the largest instances will be stuck with 32G of memory. 70G
>>>> was chosen as there are some known problems on small instances around
>>>> 80GB and the largest instance is using 68GB.
>>>>
>>>> Signed-off-by: Stefan Bader<stefan.bader at canonical.com>
>>>> ---
>>>>    debian.master/config/config.common.ubuntu |    2 +-
>>>>    1 files changed, 1 insertions(+), 1 deletions(-)
>>>>
>>>> diff --git a/debian.master/config/config.common.ubuntu
>>>> b/debian.master/config/config.common.ubuntu
>>>> index b0c486b..ed8ad01 100644
>>>> --- a/debian.master/config/config.common.ubuntu
>>>> +++ b/debian.master/config/config.common.ubuntu
>>>> @@ -5014,7 +5014,7 @@ CONFIG_XEN_COMPAT_XENFS=y
>>>>    CONFIG_XEN_DEV_EVTCHN=m
>>>>    CONFIG_XEN_FBDEV_FRONTEND=m
>>>>    CONFIG_XEN_KBDDEV_FRONTEND=m
>>>> -CONFIG_XEN_MAX_DOMAIN_MEMORY=32
>>>> +CONFIG_XEN_MAX_DOMAIN_MEMORY=70
>>>>    CONFIG_XEN_SAVE_RESTORE=y
>>>>    CONFIG_XEN_SCRUB_PAGES=y
>>>>    CONFIG_XEN_SYS_HYPERVISOR=y
>>>
>>> Any thoughts on the impact this change will have on -generic and
>>> -server? Perhaps we should restrict this change to the -ec2 flavour only.
>>>
>>> rtg
>>
>> As far as I understand it, this value is only used in the xen mmu code when
>> setting up domU. The comment there says, it is in that case using a page per GB.
>> But as we have the virtual flavour, it probably makes sense to use it.
>>
>> -Stefan
>>
>
> Ok, so here the version 2 which only changes amd64-virtual
>
> -Stefan
>

Acked-by: Tim Gardner <tim.gardner at canonical.com>

-- 
Tim Gardner tim.gardner at canonical.com



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