From 5b55072f22ba2ed136b7a1b6c5beea9ace8415a7 Mon Sep 17 00:00:00 2001 From: "Joel Fernandes (Google)" Date: Sun, 13 May 2018 20:15:40 -0700 Subject: [PATCH] rcu: Produce last "CleanupMore" trace only if late-breaking request Currently Tree RCU's clean-up code emits a "CleanupMore" trace event in response to late-arriving grace-period requests even if the grace period was already requested. This makes "CleanupMore" show up an extra time (in addition to once for each rcu_node structure that was previously marked with the request), and for no good reason. This commit therefore avoids emitting this trace message unless the the only request for this next grace period arrived during or after the cleanup scan of the rcu_node structures. Signed-off-by: Joel Fernandes (Google) Signed-off-by: Paul E. McKenney --- 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 24a79e85b81f..73a33b82cfcd 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2069,7 +2069,7 @@ static void rcu_gp_cleanup(struct rcu_state *rsp) rsp->gp_state = RCU_GP_IDLE; /* Check for GP requests since above loop. */ rdp = this_cpu_ptr(rsp->rda); - if (ULONG_CMP_LT(rnp->gp_seq, rnp->gp_seq_needed)) { + if (!needgp && ULONG_CMP_LT(rnp->gp_seq, rnp->gp_seq_needed)) { trace_rcu_this_gp(rnp, rdp, rnp->gp_seq_needed, TPS("CleanupMore")); needgp = true;