From 85f2b60c4321b088ba08ec9a05b8a7b68e4ada2a Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 11 Mar 2019 15:45:13 -0700 Subject: 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: Joel Fernandes Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel/rcu/tree.c') diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 466299c3d2da..e117732bcd5d 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -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) -- cgit v1.2.3