On 12/01/20 22:30, Will Deacon wrote: > On Tue, Dec 01, 2020 at 03:56:49PM +0000, Quentin Perret wrote: > > On Tuesday 01 Dec 2020 at 14:11:21 (+0000), Qais Yousef wrote: > > > For cpusets, if hotunplug results in an empty cpuset, then all tasks are moved > > > to the nearest ancestor if I read the code correctly. In our case, only 32bit > > > tasks have to move out to retain this behavior. Since now for the first time we > > > have tasks that can't run on all cpus. > > > > > > Which by the way might be the right behavior for 64bit tasks execing 32bit > > > binary in a 64bit only cpuset. I suggested SIGKILL'ing them but maybe moving > > > them to the nearest ancestor too is more aligned with the behavior above. > > > > Hmm, I guess that means putting all 32-bit-execd-from-64-bit tasks in > > the root group in Android. I'll try and check the implications, but that > > might be just fine... Sounds like a sensible behaviour to me anyways. > > I'll look into this -- anything we can do to avoid forcefully resetting the > affinity mask to the arch_task_cpu_possible_mask() is worth considering. Happy to lend a hand, just let me know. Thanks -- Qais Yousef
