On 12/17/20 8:10 PM, Ira Weiny wrote: > On Thu, Dec 17, 2020 at 12:41:50PM -0800, Dave Hansen wrote: >> On 11/6/20 3:29 PM, ira.weiny@xxxxxxxxx wrote: >>> void disable_TSC(void) >>> @@ -644,6 +668,8 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p) >>> >>> if ((tifp ^ tifn) & _TIF_SLD) >>> switch_to_sld(tifn); >>> + >>> + pks_sched_in(); >>> } >> >> Does the selftest for this ever actually schedule()? > > At this point I'm not sure. This code has been in since the beginning. So its > seen a lot of soak time. Think about it another way. Let's say this didn't get called on the first context switch away from the PKS-using task. Would anyone notice? How likely is this to happen? The function tracers or kprobes tend to be a great tool for this, at least for testing whether the code path you expect to hit is getting hit.