On Wed 18-09-24 11:37:42, Frederic Weisbecker wrote: > Le Tue, Sep 17, 2024 at 01:07:25PM +0200, Michal Hocko a écrit : [...] > > I am not objecting to patch per se. I am just not sure this is really > > needed. It is great to have kernel threads bound to non isolated cpus by > > default if they have node preferences. But as soon as somebody starts > > offlining cpus excessively and make the initial cpumask empty then > > select_fallback_rq sounds like the right thing to do. > > > > Not my call though. I was just curious why this is needed and it seems > > to me you are looking for some sort of correctness for broken setups. > > It looks like it makes sense to explore that path. We still need the > cpu up probe to reaffine when a suitable target comes up. But it seems > the CPU down part can be handled by select_fallback_rq. I'll try that. THanks! Btw. when you are looking at this, would it make sense to make select_fallback_rq more cpu isolation aware as well? I mean using housekeeping cpus before falling back to task_cpu_possible_mask? -- Michal Hocko SUSE Labs
