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| author |   Paul E. McKenney <paulmck@linux.ibm.com> | 2019-03-11 15:45:13 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.ibm.com> | 2019-03-26 14:38:38 -0700 |
| commit | 85f2b60c4321b088ba08ec9a05b8a7b68e4ada2a (patch) | |
| tree | 8cd995e818cc4de8f10482383af6b41a55586ef1 | |
| parent | rcu: Do a single rhp->func read in rcu_head_after_call_rcu() (diff) | |
| download | linux-dev-85f2b60c4321b088ba08ec9a05b8a7b68e4ada2a.tar.xz linux-dev-85f2b60c4321b088ba08ec9a05b8a7b68e4ada2a.zip | |
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 <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
| -rw-r--r-- | kernel/rcu/tree.c | 3 |
1 files changed, 2 insertions, 1 deletions
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) |