On 12/13/2013 09:10 AM, Mel Gorman wrote: > From: Johannes Weiner <[email protected]> > > Dave Hansen noted a regression in a microbenchmark that loops around > open() and close() on an 8-node NUMA machine and bisected it down to > 81c0a2bb515f ("mm: page_alloc: fair zone allocator policy"). That > change forces the slab allocations of the file descriptor to spread > out to all 8 nodes, causing remote references in the page allocator > and slab. > > The round-robin policy is only there to provide fairness among memory > allocations that are reclaimed involuntarily based on pressure in each > zone. It does not make sense to apply it to unreclaimable kernel > allocations that are freed manually, in this case instantly after the > allocation, and incur the remote reference costs twice for no reason. > > Only round-robin allocations that are usually freed through page > reclaim or slab shrinking. > > Cc: <[email protected]> > Bisected-by: Dave Hansen <[email protected]> > Signed-off-by: Johannes Weiner <[email protected]> > Signed-off-by: Mel Gorman <[email protected]>
Reviewed-by: Rik van Riel <[email protected]> -- All rights reversed -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
