Messages in this thread Patch in this message | | | From | "Paul E. McKenney" <> | Subject | [PATCH tip/core/rcu 12/18] rcu: Default jiffies_to_sched_qs to jiffies_till_sched_qs | Date | Tue, 26 Mar 2019 16:13:08 -0700 |
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From: Neeraj Upadhyay <neeraju@codeaurora.org>
The current code only calls adjust_jiffies_till_sched_qs() if jiffies_till_sched_qs is left at its default value, so when the jiffies_till_sched_qs kernel-boot parameter actually is specified, jiffies_to_sched_qs will be left with the value zero, which will result in useless slowdowns of cond_resched(). This commit therefore changes rcu_init_geometry() to unconditionally invoke adjust_jiffies_till_sched_qs(), which ensures that jiffies_to_sched_qs will be initialized in all cases, thus maintaining good cond_resched() performance.
Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com> --- kernel/rcu/tree.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 139fa1f5c537..466299c3d2da 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3739,8 +3739,7 @@ static void __init rcu_init_geometry(void) jiffies_till_first_fqs = d; if (jiffies_till_next_fqs == ULONG_MAX) jiffies_till_next_fqs = d; - if (jiffies_till_sched_qs == ULONG_MAX) - adjust_jiffies_till_sched_qs(); + adjust_jiffies_till_sched_qs(); /* If the compile-time values are accurate, just leave. */ if (rcu_fanout_leaf == RCU_FANOUT_LEAF && -- 2.17.1
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