On Sat, Oct 04, 2014 at 09:50:04AM -0500, Chuck Ebbert wrote: > Try playing with /proc/sys/kernel/sched_migration_cost_ns. This sets > the number of nanoseconds the kernel will wait before considering > moving a thread to another CPU. I have mine set to 50000000.
I can't get any good effect out of this. I tried both 50 ms (your value) and 500 ms, and while it seems (by eyeballing the per-cpu display in top) to _sometimes_ lock the processes to cores, more often than not, they still bounce around between all 40. Worse still, when it _does_, it seems to often lock them to hyperthread pairs (e.g., I've seen it put threads only on virtual cores 0-9 and 20-29, which means it has all of them on one socket!) Notwithstanding top, the benchmarks don't improve; setting cores manually with taskset still is much better. /* Steinar */ -- Homepage: http://www.sesse.net/ -- 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/
