On 18/06/20 09:07, Sebastian Andrzej Siewior wrote: > On 2020-06-17 17:49:48 [-0500], Scott Wood wrote: >> > Makes sense, but what about the rest of the checks? Further down there is >> > >> > /* Can the task run on the task's current CPU? If so, we're done >> > */ >> > if (cpumask_test_cpu(task_cpu(p), new_mask)) >> > goto out; >> > >> > If the task is currently migrate disabled and for some stupid reason it >> > gets affined elsewhere, we could try to move it out - which AFAICT we >> > don't >> > want to do because migrate disabled. So I suppose you'd want an extra >> > bailout condition here when the task is migrate disabled. >> > >> > ISTR in RT you do re-check the affinity and potentially move the task away >> > when re-enabling migration, so that should work out all fine. >> >> On RT the above test is: >> >> /* Can the task run on the task's current CPU? If so, we're done */ >> if (cpumask_test_cpu(task_cpu(p), new_mask) || >> p->cpus_ptr != &p->cpus_mask) >> goto out; >> >> ...so we do bail out if we're migrate disabled. > > correct. There is a complete migrate_disable() patch in the RT queue > which has to wait. This patch however looked to be independent of that > and could "fix" the pointer part which is already here so I sent it. >
Okay, thanks. I don't see any harm in including that extra check with the patch, but either way: Reviewed-by: Valentin Schneider <valentin.schnei...@arm.com> >> -Scott > > Sebastian