cpustart shows a stale gp_seq. This is because rdp->gp_seq is updated only at the end of the __note_gp_changes function. For this reason, use rnp->gp_seq instead. I believe we can't update rdp->gp_seq too early so lets just use the gp_seq from rnp instead.
Signed-off-by: Joel Fernandes (Google) <j...@joelfernandes.org> --- kernel/rcu/tree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 25c44328d071..58d2b68f8b98 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1807,7 +1807,7 @@ static bool __note_gp_changes(struct rcu_state *rsp, struct rcu_node *rnp, * set up to detect a quiescent state, otherwise don't * go looking for one. */ - trace_rcu_grace_period(rsp->name, rdp->gp_seq, TPS("cpustart")); + trace_rcu_grace_period(rsp->name, rnp->gp_seq, TPS("cpustart")); need_gp = !!(rnp->qsmask & rdp->grpmask); rdp->cpu_no_qs.b.norm = need_gp; rdp->rcu_qs_ctr_snap = __this_cpu_read(rcu_dynticks.rcu_qs_ctr); -- 2.17.0.441.gb46fe60e1d-goog