On Sat, Feb 17, 2018 at 11:50:52AM +0100, Thomas Gleixner wrote: > On Thu, 15 Feb 2018, Frederic Weisbecker wrote: > > > When a CPU runs in full dynticks mode, a 1Hz tick remains in order to > > keep the scheduler stats alive. However this residual tick is a burden > > for bare metal tasks that can't stand any interruption at all, or want > > to minimize them. > > > > The usual boot parameters "nohz_full=" or "isolcpus=nohz" will now > > outsource these scheduler ticks to the global workqueue so that a > > housekeeping CPU handles those remotely. The sched_class::task_tick() > > implementations have been audited and look safe to be called remotely > > as the target runqueue and its current task are passed in parameter > > and don't seem to be accessed locally. > > That scares me a bit. Not for the current state of affairs, but we want to > ensure that this still works in 2 years from now > > So at least you want to add a comment to task_tick() which explains the > constraints which come with the remote tick.
Good point, I'm adding that. > > Other than that this looks good! > > Reviewed-by: Thomas Gleixner <t...@linutronix.de> Thanks!
