On Fri, Dec 11, 2020 at 10:50:02PM +0000, Mel Gorman wrote: > > > The third potential downside is that the SMT sibling is not guaranteed to > > > be checked due to SIS_PROP throttling but in the old code, that would have > > > been checked by select_idle_smt(). That might result in premature stacking > > > of runnable tasks on the same CPU. Similarly, as __select_idle_core may > > > find multiple idle candidates, it will not pick the targets SMT sibling > > > if it is idle like select_idle_smt would have. > > > > > > That said, I am skeptical that select_idle_smt() matters all that often. > > > > This, I didn't really believe in it either. > > > > Good because I think any benefit from select_idle_smt is so marginal > that it should be ignored if the full scan is simpler overall.
Perhaps we should start out with a simple patch removing that pass.. That should show, what, if anything, the effect of it is.
