From: Paul E. McKenney Date: Mon, 11 Mar 2019 22:45:13 +0000 (-0700) Subject: rcu: Update jiffies_to_sched_qs and adjust_jiffies_till_sched_qs() comments X-Git-Tag: v5.2-rc1~212^2^2^2^3~4 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=85f2b60c4321b088ba08ec9a05b8a7b68e4ada2a;p=users%2Fjedix%2Flinux-maple.git 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 --- diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 466299c3d2da6..e117732bcd5d7 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)