> > > > To avoid this, please check for isolated cpus before choosing a target > > cpu. > > > > Hmm, would this also prevent a task running inside a cgroup that is > allowed accessed to isolated CPUs from balancing? I severely doubt it
Scheduler doesn't do any kind of load balancing for isolated cpus. # grep -o "isolcpus=.*" /proc/cmdline isolcpus=56,64,72,80,88 # taskset -c "56,64,72,80" ebizzy -S 100 -t 44 (on another terminal) # pgrep ebizzy 10437 # cat /proc/10437/status |grep Cpus_allowed_list Cpus_allowed_list: 56,64,72,80 # But the all the tasks would only run on cpu 56, even if its fully overloaded. Cpus 64,72,80 would be completely idle. So on isolated cpus, its the user who is in full control of scheduling the tasks on the cpu. > matters because if a process is isolated from interference then it > follows that automatic NUMA balancing should not be involved. If Yes, as an extension of the above, numa balancing should not be involved. > anything the protection should be absolute but either way; > > Acked-by: Mel Gorman <mgor...@techsingularity.net> > Thanks.
