Messages in this thread | | | Date | Thu, 8 Oct 2015 11:00:12 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH tip/core/rcu 04/18] rcu: Use single-stage IPI algorithm for RCU expedited grace period |
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On Wed, Oct 07, 2015 at 09:14:45AM -0700, Paul E. McKenney wrote: > On Wed, Oct 07, 2015 at 03:49:29PM +0200, Peter Zijlstra wrote: > > 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! > > But why not make the less-likely paths a bit cheaper while we are at it? ;-)
True, less critical, but if we're almost there we might as well fix that up too.
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