Messages in this thread | | | Date | Thu, 15 Oct 2020 11:52:35 +0200 | From | Peter Zijlstra <> | Subject | Re: [tip: locking/core] lockdep: Fix lockdep recursion |
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On Thu, Oct 15, 2020 at 11:49:26AM +0200, Peter Zijlstra wrote: > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -1764,8 +1764,7 @@ static bool rcu_gp_init(void) > smp_mb(); // Pair with barriers used when updating ->ofl_seq to odd values. > firstseq = READ_ONCE(rnp->ofl_seq); > if (firstseq & 0x1) > - while (firstseq == smp_load_acquire(&rnp->ofl_seq)) > - schedule_timeout_idle(1); // Can't wake unless RCU is watching. > + smp_cond_load_relaxed(&rnp->ofl_seq, VAL == firstseq);
My bad, that should be: VAL != firstseq.
> smp_mb(); // Pair with barriers used when updating ->ofl_seq to even values. > raw_spin_lock(&rcu_state.ofl_lock); > raw_spin_lock_irq_rcu_node(rnp);
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