On (17/09/07 15:00), Christoph Lameter didst pronounce:
As Nick points out, having to configure something makes it a #2
solution. However, I at least am ok with that. ZONE_MOVABLE is a get-out
clause to be able to control fragmentation no matter what the workload is
as it gives hard guarantees. Even when ZONE_MOVABLE is replaced by some
mechanism in grouping pages by mobility to force a number of blocks to be
MIGRATE_MOVABLE_ONLY, the emergency option will exist,
We still lack data on what sort of workloads really benefit from large
blocks (assuming there are any that cannot also be solved by improving
order-0). With Christophs approach + grouping pages by mobility +
ZONE_MOVABLE-if-it-screws-up, people can start collecting that data over the
course of the next few months while we're waiting for fsblock or software
pagesize to mature.
Do we really need to keep discussing this as no new point has been made ina
while? Can we at least take out the non-contentious parts of Christoph's
patches such as the page cache macros and do something with them?
--
Mel "tired of typing" Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab
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