VIMAGE: Freed UMA keg was not empty

[Brandon Gooch]

On Wed, Nov 17, 2010 at 7:17 AM, Bjoern A. Zeeb
<bzeeb-lists at lists.zabbadoz.net> wrote:
> On Wed, 17 Nov 2010, Marko Zec wrote:
>
>> Actually, we never seriously discussed or revisited the issue with
>> separate
>> UMA pools for each vnet instance.
>>
>> My original motivation when O introduced separate UMA pools was primarily
>> in
>> making it easier to spot resource leaks, and to prove the correctness of
>> the
>> whole VIMAGE / VNET thing.  Having more or less achieved those goals,
>> perhaps
>> the time has come to move on.  Having said that, and given that the
>> current
>> VIMAGE resource allocation model is far from being optimal (a lot of
>> memory
>> sits reserved but 99% unused, and cannot be reclaimed later on vnet
>> teardown), perhaps it's time that we reconsider using unified UMA pools.
>
> I think there is a misunderstanding here;  it can be reclaimed by the
> time we have the teardown properly sorted out and it will immediately
> help normal non-VIMAGE systems under memory pressure as well.
> The problem is that, at least for TCP (and UDP in one special case as
> I found after lots of testing), we are no there yet.
>
> After that, when it comes to resource usage, I am still wondering how
> trasz' resource limits will plug into that.  By the time we can see
> those coming together we should be able to decide whether to go left
> or right.
>

I've been running into this memory exhaustion as well, having a need
to stop and start my VIMAGE jails frequently.

I'm confident that the proper solution will be worked out, but I
wonder what sort of time-frame we may be looking at -- is VIMAGE
expected to be production by 9.0-RELEASE? Also, does anyone know the
current status of trasz's work (which I believe is to be completed
December of this year)? I hope it's still on schedule :)

-Brandon