On Tue, 28 Jan 2020 08:39:42 +0800 Wei Yang <richardw.yang@xxxxxxxxxxxxxxx> wrote: > >Is there ever a situation where the cpu to be onlined would have appeared > >in the cpumask of another node and so a different kswapd's cpumask would > >now include an off-node cpu? > > No, I don't think so. > > Per my understanding, kswapd_cpu_online() will be invoked when a cpu is > onlined. And the particular cpu belongs to a particular numa node. So it is > not necessary to iterate on every nodes. > > And current code use cpumask_and_any() to do the check. If my understanding is > correct, the check would return true if this node has any online cpu. This is > likely to be true. > > This is why I want to make the logic clear. Please resend with a changelog which explains the above?
