Re: [PATCH tip/core/rcu 04/18] rcu: Use single-stage IPI algorithm for RCU expedited grace period

From: Peter Zijlstra
Date: Wed Oct 07 2015 - 09:49:45 EST


On Wed, Oct 07, 2015 at 03:43:11PM +0200, Peter Zijlstra wrote:
> On Tue, Oct 06, 2015 at 09:29:23AM -0700, Paul E. McKenney wrote:
> > @@ -167,42 +307,18 @@ static void rcu_preempt_note_context_switch(void)
>
> > - raw_spin_unlock_irqrestore(&rnp->lock, flags);
>
> This again reminds me that we should move rcu_note_context_switch()
> under the IRQ disable section the scheduler already has or remove the
> IRQ disable from rcu_note_context_switch().

Ah, this is the unlikely path where we actually need to do work. The
normal fast paths no longer require IRQs disabled, you already fixed
that last time, good!
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/