On Sat, 29 Oct 2011, Gilad Ben-Yossef wrote: > >> +/* Which CPUs have per cpu pages */ > >> +cpumask_var_t cpus_with_pcp; > >> +static DEFINE_PER_CPU(unsigned long, total_cpu_pcp_count); > > > > Does the flushing happen so frequently that it is worth keeping this > > state on a per-cpu basis, or would it be better to check each CPU's > > pcp info and assemble a cpumask at flush time like done in patch 5? > > > > No, I don't believe it is frequent at all. I will try to re-work the > patch as suggested. The draining of the pcp pages is done from the vmstat callback which occurs every second. Only if there is something to clean in the caches will the flush happen.