On Thu, Nov 9, 2017 at 2:30 PM, Rafael J. Wysocki <raf...@kernel.org> wrote: > > c_start() can run aperfmperf_snapshot_khz() on all CPUs upfront (say > in parallel), then wait for a while (say 5 ms; the current 20 ms wait > is overkill) and then aperfmperf_snapshot_khz() can be run once on > each CPU in show_cpuinfo() without taking the "stale cache" threshold > into account.
Yeah, that won't work. What could work is to do that "smp_call_function_many()" at open time, and *not* set the "wait" flag, but do it entirely asynchronously. But I don't think that's an option for 4.14 ;( So I guess I'll have to revert. Linus