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authorPaul E. McKenney <paul.mckenney@linaro.org>2012-05-05 19:10:35 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2012-06-06 20:43:27 -0700
commitfd4b352687fd8604d49c190c4c9ea9e369fd42d5 (patch)
tree1e20de9090f7d74eef642ac263dd71da0b494d7d /kernel
parentrcu: RCU_FAST_NO_HZ detection of callback adoption (diff)
downloadlinux-dev-fd4b352687fd8604d49c190c4c9ea9e369fd42d5.tar.xz
linux-dev-fd4b352687fd8604d49c190c4c9ea9e369fd42d5.zip
rcu: Update RCU_FAST_NO_HZ tracing for lazy callbacks
In the current code, a short dyntick-idle interval (where there is at least one non-lazy callback on the CPU) and a long dyntick-idle interval (where there are only lazy callbacks on the CPU) are traced identically, which can be less than helpful. This commit therefore emits different event traces in these two cases. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/rcutree_plugin.h8
1 files changed, 5 insertions, 3 deletions
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 2411000d9869..5449f02c4820 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -2165,15 +2165,17 @@ static void rcu_prepare_for_idle(int cpu)
!rcu_pending(cpu) &&
!local_softirq_pending()) {
/* Can we go dyntick-idle despite still having callbacks? */
- trace_rcu_prep_idle("Dyntick with callbacks");
per_cpu(rcu_dyntick_drain, cpu) = 0;
per_cpu(rcu_dyntick_holdoff, cpu) = jiffies;
- if (rcu_cpu_has_nonlazy_callbacks(cpu))
+ if (rcu_cpu_has_nonlazy_callbacks(cpu)) {
+ trace_rcu_prep_idle("Dyntick with callbacks");
per_cpu(rcu_idle_gp_timer_expires, cpu) =
jiffies + RCU_IDLE_GP_DELAY;
- else
+ } else {
per_cpu(rcu_idle_gp_timer_expires, cpu) =
jiffies + RCU_IDLE_LAZY_GP_DELAY;
+ trace_rcu_prep_idle("Dyntick with lazy callbacks");
+ }
tp = &per_cpu(rcu_idle_gp_timer, cpu);
mod_timer_pinned(tp, per_cpu(rcu_idle_gp_timer_expires, cpu));
per_cpu(rcu_nonlazy_posted_snap, cpu) =