Peter Zijlstra <peterz@xxxxxxxxxxxxx> writes: > On Tue, Apr 14, 2020 at 01:06:46PM +0100, Mel Gorman wrote: >> While it's just an opinion, my preference would be to focus on reducing >> the cost and amount of scanning done -- particularly for threads. > > This; I really don't believe in those back-charging things, esp. since > not having cgroups or having multiple applications in a single cgroup is > a valid setup. Technically, it appears possible to back-charge the CPU time to the process/thread directly (not the cgroup). > Another way to reduce latency spikes is to decrease both > sysctl_numa_balancing_scan_delay and sysctl_numa_balancing_scan_size. > Then you do more smaller scans. By scanning more often you reduce the > contrast, by reducing the size you lower the max latency. Yes. This can reduce latency spikes. Best Regards, Huang, Ying > And this is all assuming you actually want numa balancing for this > process.
