Cc: Andrew Morton <akpm@...>, Nick Piggin <nickpiggin@...>, Christoph Lameter <clameter@...>, <andrea@...>, <torvalds@...>, <linux-fsdevel@...>, <linux-kernel@...>, Christoph Hellwig <hch@...>, William Lee Irwin III <wli@...>, David Chinner <dgc@...>, Jens Axboe <jens.axboe@...>, Badari Pulavarty <pbadari@...>, Maxim Levitsky <maximlevitsky@...>, Fengguang Wu <fengguang.wu@...>, swin wang <wangswin@...>, <totty.lu@...>, <hugh@...>
It would be plain impossible from a fragmentation point-of-view but you
meet interesting situations when a GFP_NOFS allocation has no kernel blocks
available to use. It can't reclaim, maybe it can move but not with current
code (it should be able to with the Memory Compaction patches).
Current code doesn't reflect your assumptions simply because the costs are so
high. We'd need to be really sure it's worth it and if the answer is "yes",
then we are looking at Andrea's approach (more likely) or I can check out
evicting blocks of 16KB, 64KB or whatever the large block is.
--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab
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