On Wed, Jan 13, 2021 at 12:36:55AM +0800, Lai Jiangshan wrote: > On Tue, Jan 12, 2021 at 10:51 PM Peter Zijlstra <[email protected]> wrote: > > > > Mark the per-cpu workqueue workers as KTHREAD_IS_PER_CPU. > > > > Workqueues have unfortunate semantics in that per-cpu workers are not > > default flushed and parked during hotplug, however a subset does > > manual flush on hotplug and hard relies on them for correctness. > > > > Therefore play silly games.. > > > > Signed-off-by: Peter Zijlstra (Intel) <[email protected]> > > Tested-by: Paul E. McKenney <[email protected]> > > --- > > Reviewed-by: Lai Jiangshan <[email protected]> > > I like this patchset in that the scheduler takes care of the > affinities of the tasks when we don't want it to be per-cpu.
Thanks! A possibly even simpler approach would be to have rebind_workers() kill all workers and have create_worker() spawn us new ones. That avoids ever having to use set_cpus_allowed_ptr() on per-cpu kthreads.... with the exception of rescuer.. still pondering that.
