On Mon, 29 Aug 2016, Michal Hocko wrote: > Compaction can certainly help and the more we are proactive in that > direction the better. Vlastimil has already done a first step in that > direction and we a have a dedicated kcompactd kernel thread for that > purpose. But I guess what Mel had in mind is the latency of higher > order pages which is inherently higher with the current page allocator > no matter how well the compaction works. There are other changes, mostly > for the fast path, needed to make higher order pages less of a second > citizen. Compaction needs to be able to move many more types of kernel objects out of the way. I think if the callbacks that were merged for the migration of CMA pages are made usable for slab allocations then we may make some progress there. This would require the creator of a slab cache to specify functions that allow the migration of an object. Would require additional subsystem specific code. But doing that for inodes and dentries could be very benficial for compaction. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>