On Thu, Mar 02, 2023 at 10:55:09AM -0300, Marcelo Tosatti wrote: > > (2) If someone can modify the dead cpu's vm_stat_diff, > > The only context that can modify the cpu's vm_stat_diff are: > > 1) The CPU itself (increases the counter). > 2) cpu_vm_stats_fold (from vmstat_shepherd kernel thread), from > x -> 0 only. I think I didn't continue reading so I didn't see cpu_vm_stats_fold() will be reused when commenting, sorry. Now with a reworked (and SMP-safe) cpu_vm_stats_fold() and vmstats, I'm wondering the possibility of merging it with refresh_cpu_vm_stats() since they really look similar. IIUC the new refresh_cpu_vm_stats() logically doesn't need the small preempt disabled sections, not anymore, if with a cpu_id passed over to cpu_vm_stats_fold(), which seems to be even a good side effect. But not sure I missed something. -- Peter Xu
