Commit 85f2b60c authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcu: Update jiffies_to_sched_qs and adjust_jiffies_till_sched_qs() comments 



This commit better documents the jiffies_to_sched_qs default-value
strategy used by adjust_jiffies_till_sched_qs()

Reported-by: default avatarJoel Fernandes <joel@joelfernandes.org>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.ibm.com>
parent b699cce1

kernel/rcu/tree.c

+2 −1
Original line number Diff line number Diff line
@@ -406,7 +406,7 @@ static bool rcu_kick_kthreads; 
 */

static ulong jiffies_till_sched_qs = ULONG_MAX;

module_param(jiffies_till_sched_qs, ulong, 0444);

static ulong jiffies_to_sched_qs; /* Adjusted version of above if not default */

static ulong jiffies_to_sched_qs; /* See adjust_jiffies_till_sched_qs(). */

module_param(jiffies_to_sched_qs, ulong, 0444); /* Display only! */



/*
@@ -424,6 +424,7 @@ static void adjust_jiffies_till_sched_qs(void) 
		WRITE_ONCE(jiffies_to_sched_qs, jiffies_till_sched_qs);

		return;

	}

	/* Otherwise, set to third fqs scan, but bound below on large system. */

	j = READ_ONCE(jiffies_till_first_fqs) +

		      2 * READ_ONCE(jiffies_till_next_fqs);

	if (j < HZ / 10 + nr_cpu_ids / RCU_JIFFIES_FQS_DIV)