On Thu, Aug 30, 2018 at 02:46:16PM +0000, Eugeniy Paltsev wrote: > On Thu, 2018-08-30 at 16:17 +0200, Peter Zijlstra wrote: > > On Thu, Aug 30, 2018 at 11:53:17AM +0000, Eugeniy Paltsev wrote: > > > I can see crashes with LLSC enabled in both SMP running on 4 cores > > > and SMP running on 1 core. > > > > So you're running on LL/SC enabled hardware; that would make Will's > > patch irrelevant (although still a good idea for the hardware that does > > care about that spinlocked atomic crud). > > > > Does something like the below cure things? That would confirm the > > suggestion that the change to __clear_bit_unlock() is the curprit. > > I tested it - this doesn't change anything, the problem still reproduces. OK, 'good' :-) > I'll test it with last Will fix. Yes, that missing "bnz 1b" is very very suspect.