On Fri, Nov 23, 2012 at 9:31 PM, Ingo Molnar <mingo@xxxxxxxxxx> wrote: > > * Ingo Molnar <mingo@xxxxxxxxxx> wrote: > >> * Alex Shi <lkml.alex@xxxxxxxxx> wrote: >> >> > > >> > > Those of you who would like to test all the latest patches are >> > > welcome to pick up latest bits at tip:master: >> > > >> > > git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git master >> > > >> > >> > I am wondering if it is a problem, but it still exists on HEAD: c418de93e39891 >> > http://article.gmane.org/gmane.linux.kernel.mm/90131/match=compiled+with+name+pl+and+start+it+on+my >> > >> > like when just start 4 pl tasks, often 3 were running on node >> > 0, and 1 was running on node 1. The old balance will average >> > assign tasks to different node, different core. >> >> This is "normal" in the sense that the current mainline >> scheduler is (supposed to be) doing something similar: if the >> node is still within capacity, then there's no reason to move >> those threads. >> >> OTOH, I think with NUMA balancing we indeed want to spread >> them better, if those tasks do not share memory with each >> other but use their own memory. If they share memory then they >> should remain on the same node if possible. I rewrite the little test case by assemble: == .text .global _start _start: do_nop: nop nop jmp do_nop == It reproduced the problem on latest tip/master, HEAD: 7cb989d0159a6f43104992f18 like for 4 above tasks running, 3 of them running on node 0, one running on node 1. If kernel can detect the LLC of CPU is allowed for tasks aggregate, it's a nice feature. if not, the aggregate may cause more cache missing. > > Could you please check tip:master with -v17: > > git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git master > > ? > > It should place your workload better than v16 did. > > Note, you might be able to find other combinations of tasks that > are not scheduled NUMA-perfectly yet, as task group placement is > not exhaustive yet. > > You might want to check which combination looks the weirdest to > you and report it, so I can fix any remaining placement > inefficiencies in order of importance. > > Thanks, > > Ingo -- Thanks Alex -- 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>