Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [patch V6 12/37] x86/entry: Provide idtentry_entry/exit_cond_rcu() | Date | Wed, 20 May 2020 21:49:18 +0200 |
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"Paul E. McKenney" <paulmck@kernel.org> writes: > On Wed, May 20, 2020 at 09:51:17AM -0700, Andy Lutomirski wrote: >> Paul, the major change here is that if an IRQ hits normal kernel code >> (i.e. code where RCU is watching and we're not in an EQS), the IRQ >> won't call rcu_irq_enter() and rcu_irq_exit(). Instead it will call >> rcu_tickle() on entry and nothing on exit. Does that cover all the >> bases? > > From an RCU viewpoint, yes, give or take my concerns about someone > putting rcu_tickle() on entry and rcu_irq_exit() on exit. Perhaps > I can bring some lockdep trickery to bear.
An surplus rcu_irq_exit() should already trigger alarms today.
> But I must defer to Thomas and Peter on the non-RCU/non-NO_HZ_FULL > portions of this.
I don't see a problem. Let me write that into actual testable patch form.
Thanks,
tglx
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