On Wed, 19 Feb 2020 06:44:22 +0800 Wei Yang <richardw.yang@xxxxxxxxxxxxxxx> wrote: > kswapd kernel thread starts either with a CPU affinity set to the full > cpu mask of its target node or without any affinity at all if the node > is CPUless. There is a cpu hotplug callback (kswapd_cpu_online) that > implements an elaborate way to update this mask when a cpu is onlined. > > It is not really clear whether there is any actual benefit from this > scheme. Completely CPU-less NUMA nodes rarely gain a new CPU during > runtime. This is the case across all platforms, all architectures, all users for the next N years? I'm surprised that we know this with sufficient confidence. Can you explain how you came to make this assertion? > Drop the code for that reason. If there is a real usecase then > we can resurrect and simplify the code.
