Hi Paul, On Thu, Jul 30, 2020 at 08:48:25PM -0700, Paul E. McKenney wrote: [...] > > And I could make the comment here as: > > /* > > * Delete QS reporting from here, by June 2021, if the warning does not > > * fire. Leave the warning indefinitely. Check RCU design requirements > > * in Documentation/RCU/ about CPU hotplug requirements. > > */ > > Rather than decide for our future selves, could we please just suggest > reviewing this on June 2021? Or, given enterprise distro schedules, > 2024. :-/ I am replacing it with the following, let me know if any objections, thanks: + * XXX: The following rcu_report_qs_rnp() is redundant. If the below + * warning does not fire, consider replacing it with the "else" block, + * by June 2021 or so. The rationale for this is as follows: The CPU + * onlining path does not need to report QS for an offline CPU. Either + * the QS should have reported during CPU offlining, or during + * rcu_gp_init() if it detected a race with either CPU offlining or + * task unblocking on previously offlined CPUs. To avoid deadlocks + * related to waiting on timers or cpu hotplug locks, only those paths + * do the QS reporting for offline CPUs. thanks, - Joel > > Thanx, Paul > > > I will post my v3 with changes to the requirements document. > > > > Let me know any other comments, thanks, > > > > - Joel > >
