Hi, On Mon, Feb 06, 2012 at 10:48:42AM -0600, Christoph Lameter wrote: > So this would mean having statistics that show how many pages are > allocated on each node and take that into consideration for load > balancing? Which is something that we felt to be desirable for a long > time. Correct. The most difficult part after collecting the per page thread affinity and per-mm (process) thread affinity, is to compute it and drive both scheduler and migrate.c in function of it. The algorithm I got seems to work but it's not easy stuff. But at least it's not intrusive, it's trivial to proof absolutely zero change of runtime behavior the moment the core daemon that drives the whole thing stops running (sysfs disable or not compiled in). There are still areas where this logic needs improvement (like migrating unmapped pagecache when node is full etc..). I'm trying to clean things up so the code will be more readable and tunable at runtime. I also need to reduce its cost when you boot the kernel on a not-numa machine (allocating the data on the pgdat instead of struct page, which is not so easy with all memory models we got that allocate the pgdat data in different places, and allocate autonuma structures pointed by mm and task struct). All structures are embedded static right now (not allocated dynamically) but making it dynamic is not difficult cleanup even it's not the top priority at the moment. The only difficult feature I still miss is native THP migration which I plan to add after complete sysfs tuning works. (khugepaged is already capable to recreate THP on destination node, but I don't like that because the migration right now leads to temporary creation of sptes instead of sticking to spmds on KVM, not to tell a lot more vmexits than if we only get one for the spmd). For no-virt probably it's not so important feature as the hugepages are recreated later and a page fault costs less than a vmexit. Thanks, Andrea -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>