Messages in this thread Patch in this message | | | Date | Wed, 31 Oct 2012 13:08:42 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH 7/9] rcu: use this_cpu_ptr per-cpu helper instead of per_cpu_ptr(p, raw_smp_processor_id()) |
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On Wed, Oct 31, 2012 at 05:47:04PM +0000, Christoph Lameter wrote: > On Wed, 31 Oct 2012, Shan Wei wrote: > > > Signed-off-by: Shan Wei <davidshan@tencent.com> > > --- > > kernel/rcutree.c | 2 +- > > 1 files changed, 1 insertions(+), 1 deletions(-) > > > > diff --git a/kernel/rcutree.c b/kernel/rcutree.c > > index 74df86b..3a21fcf 100644 > > --- a/kernel/rcutree.c > > +++ b/kernel/rcutree.c > > @@ -1960,7 +1960,7 @@ static void force_quiescent_state(struct rcu_state *rsp) > > struct rcu_node *rnp_old = NULL; > > > > /* Funnel through hierarchy to reduce memory contention. */ > > - rnp = per_cpu_ptr(rsp->rda, raw_smp_processor_id())->mynode; > > + rnp = this_cpu_ptr(rsp->rda)->mynode; > > Do > > rnp = this_cpu_read(rsp->rda->mynode); > > instad.
One thing to keep in mind -- the only purpose of this is to diffuse memory contention. So there is no need to disable preemption.
Thanx, Paul
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