Commit a738eec6 authored Mar 10, 2015 by Paul E. McKenney

rcu: Correctly initialize ->rcu_qs_ctr_snap at online time

The rcu_data structure's ->rcu_qs_ctr_snap field is initialized at
CPU-online time from the current CPU's element of the per-CPU rcu_qs_ctr
variable. Unfortunately, this is at CPU_UP_PREPARE time, so has nothing
to do with the CPU being onlined. This commit therefore initializes
this variable from the incoming CPU's element of rcu_qs_ctr.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

parent cce7f1fc

kernel/rcu/tree.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -3763,7 +3763,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
		rdp->gpnum = rnp->completed; /* Make CPU later note any new GP. */
		rdp->completed = rnp->completed;
		rdp->passed_quiesce = false;
		rdp->rcu_qs_ctr_snap = __this_cpu_read(rcu_qs_ctr);
		rdp->rcu_qs_ctr_snap = per_cpu(rcu_qs_ctr, cpu);
		rdp->qs_pending = false;
		trace_rcu_grace_period(rsp->name, rdp->gpnum, TPS("cpuonl"));
		raw_spin_unlock_irqrestore(&rnp->lock, flags);

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