From c51d7b5e6c94aa6b554c27bd2b0eb64ebef02334 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 3 Oct 2018 17:25:33 -0700 Subject: [PATCH] rcutorture: Print time since GP end upon forward-progress failure If rcutorture's forward-progress tests fail while a grace period is not in progress, it is useful to print the time since the last grace period ended as a way to detect failure to launch a new grace period. This commit therefore makes this change. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 5 ++++- kernel/rcu/tree.h | 2 ++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index f91631541965..9180158756d2 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2000,7 +2000,8 @@ static void rcu_gp_cleanup(void) WRITE_ONCE(rcu_state.gp_activity, jiffies); raw_spin_lock_irq_rcu_node(rnp); - gp_duration = jiffies - rcu_state.gp_start; + rcu_state.gp_end = jiffies; + gp_duration = rcu_state.gp_end - rcu_state.gp_start; if (gp_duration > rcu_state.gp_max) rcu_state.gp_max = gp_duration; @@ -2686,6 +2687,8 @@ void rcu_fwd_progress_check(unsigned long j) __func__, jiffies - rcu_state.gp_start); show_rcu_gp_kthreads(); } else { + pr_info("%s: Last GP end %lu jiffies ago\n", + __func__, jiffies - rcu_state.gp_end); preempt_disable(); rdp = this_cpu_ptr(&rcu_data); rcu_check_gp_start_stall(rdp->mynode, rdp, j); diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index a8f82b7dc5e2..d90b02b53c0e 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -328,6 +328,8 @@ struct rcu_state { /* force_quiescent_state(). */ unsigned long gp_start; /* Time at which GP started, */ /* but in jiffies. */ + unsigned long gp_end; /* Time last GP ended, again */ + /* in jiffies. */ unsigned long gp_activity; /* Time of last GP kthread */ /* activity in jiffies. */ unsigned long gp_req_activity; /* Time of last GP request */ -- 2.45.2