Messages in this thread | | | Date | Wed, 23 Jul 2014 05:21:12 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH 09/16] rcu: Remove redundant check for online cpu |
| |
On Wed, Jul 23, 2014 at 01:09:46AM -0400, Pranith Kumar wrote: > There are two checks for an online CPU if two if() conditions. This commit > simplies this by replacing it with only one check for the online CPU. > > Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
I admit that it is very early in the morning my time, but I don't see this change as preserving the semantics in all cases. Please recheck your changes to the second check.
Thanx, Paul
> --- > kernel/rcu/tree.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index 5dcbf36..8d598a2 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -2602,15 +2602,18 @@ static void __call_rcu_core(struct rcu_state *rsp, struct rcu_data *rdp, > { > bool needwake; > > + if (!cpu_online(smp_processor_id())) > + return; > + > /* > * If called from an extended quiescent state, invoke the RCU > * core in order to force a re-evaluation of RCU's idleness. > */ > - if (!rcu_is_watching() && cpu_online(smp_processor_id())) > + if (!rcu_is_watching()) > invoke_rcu_core(); > > - /* If interrupts were disabled or CPU offline, don't invoke RCU core. */ > - if (irqs_disabled_flags(flags) || cpu_is_offline(smp_processor_id())) > + /* If interrupts were disabled, don't invoke RCU core. */ > + if (irqs_disabled_flags(flags)) > return; > > /* > -- > 2.0.0.rc2 >
| |