shrinking memory consumptions

[Albert Cahalan]

Ivan Krstic writes:
> Jens Axboe wrote:
>> I'll push this patch locally upstream as well, perhaps we can use it
>> meanwhile. 150kb is quite a bit of memory, when all you have is 128MiB
>
> Thanks for your work on this. Despite Jim's (correct) warning that
> there is lower-hanging fruit, it's savings like these that quickly
> add up to substantial numbers. We are helped quite a bit by the
> decision to ship with 256 MB of RAM in the production machines.

In build 303, about 75 MB was consumed before an activity
even got a chance. That left about 53 MB for the activity.

I notice that the non-activity stuff isn't done yet. I hope we can
keep the currently available RAM for activities. Burning RAM on the
other stuff feels very wrong to me; the other stuff is only there
to support the activities.