From edf3775f0ad66879796f594983163f672c4bf1a2 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sun, 22 Mar 2020 14:09:45 -0700 Subject: rcu-tasks: Add count for idle tasks on offline CPUs This commit adds a counter for the number of times the quiescent state was an idle task associated with an offline CPU, and prints this count at the end of rcutorture runs and at stall time. Signed-off-by: Paul E. McKenney --- kernel/rcu/tasks.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'kernel/rcu') diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index ce658831c759..0d1b5bf8317d 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -729,6 +729,7 @@ static DEFINE_PER_CPU(bool, trc_ipi_to_cpu); // heavyweight readers executing explicit memory barriers. unsigned long n_heavy_reader_attempts; unsigned long n_heavy_reader_updates; +unsigned long n_heavy_reader_ofl_updates; void call_rcu_tasks_trace(struct rcu_head *rhp, rcu_callback_t func); DEFINE_RCU_TASKS(rcu_tasks_trace, rcu_tasks_wait_gp, call_rcu_tasks_trace, @@ -840,6 +841,8 @@ static bool trc_inspect_reader(struct task_struct *t, void *arg) !rcu_dynticks_zero_in_eqs(cpu, &t->trc_reader_nesting)) return false; // No quiescent state, do it the hard way. n_heavy_reader_updates++; + if (ofl) + n_heavy_reader_ofl_updates++; in_qs = true; } else { in_qs = likely(!t->trc_reader_nesting); @@ -1156,7 +1159,8 @@ static void show_rcu_tasks_trace_gp_kthread(void) { char buf[64]; - sprintf(buf, "N%d h:%lu/%lu", atomic_read(&trc_n_readers_need_end), + sprintf(buf, "N%d h:%lu/%lu/%lu", atomic_read(&trc_n_readers_need_end), + data_race(n_heavy_reader_ofl_updates), data_race(n_heavy_reader_updates), data_race(n_heavy_reader_attempts)); show_rcu_tasks_generic_gp_kthread(&rcu_tasks_trace, buf); -- cgit v1.2.3-59-g8ed1b