Re: Using O(1) scheduler with 600 processes.

[William Lee Irwin III <wli@holomorphy.com>]

At some point in the past, someone else wrote:
>> So I decided to try 2.4.20aa1 instead, reversing the xfs patches, and
>> then updating with a newer code base, worse problems reversing those xfs
>> patches. 
>> SO I decided to just roll my own with the known features we use in
>> production.
>> 2.4.20 + xfs + lvm106 + rmap or aavm + O(1) sched + pte-highmem. 

On Thu, Jan 23, 2003 at 10:48:19PM -0800, Martin J. Bligh wrote:
> If you have enough ptes to want pte-highmem, I doubt you want rmap.
> pte-chain space consumption will kill you. The calculations are pretty
> easy to work out as to what the right solution is for your setup.

Basically vma-based ptov resolution needs to be implemented for private
anonymous pages, which will require much less ZONE_NORMAL space overhead
as pte_chains may then be chucked.

Dropping physical scanning altogether would be a mistake esp. for boxen
of any appreciable amount of physical locality (NUMA, big highmem
penalties, etc.) or wishing to support any significant number of tasks.


-- wli