On Wed, 5 Sep 2018, Neeraj Upadhyay wrote: > On 09/05/2018 05:53 PM, Thomas Gleixner wrote: > > > > And looking closer this is a general issue. Just that the TEARDOWN state > > makes it simple to observe. It's universaly broken, when the first teardown > > callback fails because, st->state is only decremented _AFTER_ the callback > > returns success, but undo_cpu_down() increments unconditionally. > > > > As per my understanding, there are 2 problems here; one is fixed with your > patch, and other is cpuhp_reset_state() is used during rollback from non-AP to > AP state, which seem to result in 2 increments of st->state (one increment > done by cpuhp_reset_state() and another by cpu_thread_fun()) . And how did your hack fix that up magically? I'll have a look later today. Thanks, tglx
