On Tue, Sep 18, 2018 at 03:22:13PM +0200, Jan H. Schönherr wrote: > On 09/17/2018 11:48 AM, Peter Zijlstra wrote: > > On Sat, Sep 15, 2018 at 10:48:20AM +0200, Jan H. Schönherr wrote: > >> On 09/14/2018 06:25 PM, Jan H. Schönherr wrote: > > > >>> b) ability to move CFS RQs between CPUs: someone changed the affinity of > >>> a cpuset? No problem, just attach the runqueue with all the tasks > >>> elsewhere. > >>> No need to touch each and every task. > > > > Can't do that, tasks might have individual constraints that are tighter > > than the cpuset. > > AFAIK, changing the affinity of a cpuset overwrites the individual affinities > of tasks > within them. Thus, it shouldn't be an issue.
No, it only shrinks the set. Also nothing stops you calling sched_setaffinity() once you're inside the cpuset. The only contraint is that your mask is a subset of the cpuset mask.
