Hello, On Wed, Oct 18, 2023 at 03:18:52PM -0400, Waiman Long wrote: > I have a second thought after taking a further look at that. First of all, > cpuset_allowed_mask isn't relevant here and the mask can certainly contain > offline CPUs. So cpu_possible_mask is the proper fallback. > > With the current patch, wq_user_unbound_cpumask is set up initially as > (HK_TYPE_WQ ∩ HK_TYPE_DOMAIN) house keeping mask and rewritten by any > subsequent write to workqueue/cpumask sysfs file. So using The current behavior is not something which is carefully planned. It's more accidental than anything. If we can come up with a more intutive and consistent behavior, that should be fine. > wq_user_unbound_cpumask has the implied precedence of user-sysfs written > mask, command line isolcpus or nohz_full option mask and cpu_possible_mask. > I think just fall back to wq_user_unbound_cpumask if the operation fails > should be enough. But yeah, that sounds acceptable. Thanks. -- tejun