> Given work canceled because per-CPU pages can be freed remotely from > housekeeping CPUs (see patch 3/5), what is added here is not needed. Hi Hillf, Firstly, apologies for the delay! The concern is to ensure CPU-specific vmstat counters are reset and folded into NUMA node and zone specific and global counters too before entering idle. It is necessary to invoke quiet_vmstat() on return to idle even if the scheduling-clock tick has been previously stopped. Please refer to the complete scenario I described again. If I understand correctly, indeed the remote drain/or free of zone CPU-specific pages can be initiated by a "housekeeping" CPU i.e. refresh_cpu_vm_stats(true) via a worker thread/or kworker, yet the actual free will only occur when the nohz_full CPU exits idle code and calls schedule_idle(). Kind regards, -- Aaron Tomlin
