From: Paul E. McKenney Date: Tue, 10 Mar 2015 21:53:29 +0000 (-0700) Subject: rcu: Correctly initialize ->rcu_qs_ctr_snap at online time X-Git-Tag: firefly_0821_release~176^2~1636^2^2^4~2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a738eec6c6082f48cbcf0157fd9f550e286ea04b;p=firefly-linux-kernel-4.4.55.git 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 --- diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index a1df68fce545..d198a33d54bd 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -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);