On Wed, 1 Mar 2017 10:44:09 +0100 Peter Zijlstra <pet...@infradead.org> wrote:
> On Tue, Feb 28, 2017 at 03:50:30PM -0500, Steven Rostedt wrote: > > + * The overloaded RT CPU, wher receiving an IPI, will try to push off its > > "wher" isn't in my dictionary, I'm thinking you mean: "when". Fixed that > for you. Heh, thanks. Hmm, I looked at all the highlighted words when I pulled in the patch into claws-mail. I'm surprised I missed that. > > > + * overloaded RT tasks and then send an IPI to the next CPU that has > > + * overloaded RT tasks. This stops when all CPUs with overloaded RT tasks > > + * have completed. Just because a CPU may have pushed off its own > > overloaded > > + * RT task does not mean it should stop sending the IPI around to other > > + * overloaded CPUs. There may be another RT task waiting to run on one of > > + * those CPUs that are of higher priority than the one that was just > > + * pushed. > > + * > > + * An optimization that could possibly be made is to make a CPU array > > similar > > + * to the cpupri array mask of all running RT tasks, but for the overloaded > > + * case, then the IPI could be sent to only the CPU with the highest > > priority > > + * RT task waiting, and that CPU could send off further IPIs to the CPU > > with > > + * the next highest waiting task. Since the overloaded case is much less > > likely > > + * to happen, the complexity of this implementation may not be worth it. > > + * Instead, just send an IPI around to all overloaded CPUs. > > Yeah, not sure, I'll leave it in though. OK, Thanks! -- Steve
