On 2018-11-19 07:08:44 [-0800], Dave Hansen wrote: > On 11/19/18 7:06 AM, Sebastian Andrzej Siewior wrote: > > On 2018-11-19 07:04:35 [-0800], Dave Hansen wrote: > >> Does the local_bh_disable() itself survive? > > Not in __fpu__restore_sig(). I do have: > > | static inline void __fpregs_changes_begin(void) > > | { > > | preempt_disable(); > > | local_bh_disable(); > > | } > > > > and __fpregs_changes_begin() is introduced as part of the series. > > OK, so can we just comment *that*, please? Basically, why do we need botj? let me do this then. local_bh_disable() should be enough. However I had a discussion with PeterZ that this (local_bh_disable()) also acting as preempt_disable()) is an implementation detail and should be avoided. It is not true Preempt-RT for instance. Sebastian