Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [patch 03/63] sched: Prepare for RT sleeping spin/rwlocks | Date | Tue, 03 Aug 2021 16:04:07 +0200 |
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On Tue, Aug 03 2021 at 11:48, Peter Zijlstra wrote:
> On Sun, Aug 01, 2021 at 05:30:06PM +0200, Mike Galbraith wrote: >> On Fri, 2021-07-30 at 15:50 +0200, Thomas Gleixner wrote: >> > >> > --- a/include/linux/sched.h >> > +++ b/include/linux/sched.h >> > @@ -155,6 +155,27 @@ struct task_group; >> > WRITE_ONCE(current->__state, (state_value)); \ >> > raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ >> > } while (0) >> > + >> > + >> > +#define current_save_and_set_rtlock_wait_state() \ >> > + do { \ >> > + raw_spin_lock(¤t->pi_lock); \ > > That wants to be irqsafe methinks, I realize this is PREEMPT_RT only and > there the _irqfoo crap is a no-op so this doesn't really matter one way > or the other, but still, taking PI lock without IRQ disable makes my > head go BUG-BUG-BUG :-)
Actually the rule to lock PI lock irqsave still persists on RT, but this has to be called with interrupts disabled (rtmutex::wait_lock is held), so adding a lockdep_assert_irqs_disable() might be good enough to spare the extra save/restore. Hmm?
Thanks,
tglx
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