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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2016-06-29 17:04:19 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2016-08-22 09:30:42 -0700
commit98834b83785e1388fa8672cf4f8de09974d15e86 (patch)
tree0d5e2ac04b2ee8785674c4471c9ddae07d728174 /kernel/rcu
parent24a6cff286030b98149ff10b968cba31280fcb7a (diff)
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rcu: Exclude RCU-offline CPUs from expedited grace periods
The expedited RCU grace periods currently rely on a failure indication from smp_call_function_single() to determine that a given CPU is offline. This works after a fashion, but is more contorted and less precise than relying on RCU's internal state. This commit therefore takes a first step towards relying on internal state. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/tree_exp.h3
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index f316683b18f1..3bc4b3dda801 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -359,7 +359,8 @@ static void sync_rcu_exp_select_cpus(struct rcu_state *rsp,
struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
if (raw_smp_processor_id() == cpu ||
- !(atomic_add_return(0, &rdtp->dynticks) & 0x1))
+ !(atomic_add_return(0, &rdtp->dynticks) & 0x1) ||
+ !(rnp->qsmaskinitnext & rdp->grpmask))
mask_ofl_test |= rdp->grpmask;
}
mask_ofl_ipi = rnp->expmask & ~mask_ofl_test;