diff options
Diffstat (limited to 'kernel/rcutree_plugin.h')
| -rw-r--r-- | kernel/rcutree_plugin.h | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index b70ca8cc52e..6467f5669ab 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -2031,10 +2031,13 @@ static void rcu_prepare_for_idle(int cpu) /* If no callbacks or in the holdoff period, enter dyntick-idle. */ if (!rcu_cpu_has_callbacks(cpu)) { per_cpu(rcu_dyntick_holdoff, cpu) = jiffies - 1; + trace_rcu_prep_idle("No callbacks"); return; } - if (per_cpu(rcu_dyntick_holdoff, cpu) == jiffies) + if (per_cpu(rcu_dyntick_holdoff, cpu) == jiffies) { + trace_rcu_prep_idle("In holdoff"); return; + } /* Check and update the rcu_dyntick_drain sequencing. */ if (per_cpu(rcu_dyntick_drain, cpu) <= 0) { @@ -2044,9 +2047,11 @@ static void rcu_prepare_for_idle(int cpu) /* We have hit the limit, so time to give up. */ per_cpu(rcu_dyntick_holdoff, cpu) = jiffies; if (!rcu_pending(cpu)) { + trace_rcu_prep_idle("Dyntick with callbacks"); per_cpu(rcu_awake_at_gp_end, cpu) = 1; return; /* Nothing to do immediately. */ } + trace_rcu_prep_idle("Begin holdoff"); invoke_rcu_core(); /* Force the CPU out of dyntick-idle. */ return; } @@ -2073,9 +2078,15 @@ static void rcu_prepare_for_idle(int cpu) c = c || per_cpu(rcu_bh_data, cpu).nxtlist; } - /* If RCU callbacks are still pending, RCU still needs this CPU. */ - if (c) + /* + * If RCU callbacks are still pending, RCU still needs this CPU. + * So try forcing the callbacks through the grace period. + */ + if (c) { + trace_rcu_prep_idle("More callbacks"); invoke_rcu_core(); + } else + trace_rcu_prep_idle("Callbacks drained"); } /* @@ -2085,6 +2096,7 @@ static void rcu_prepare_for_idle(int cpu) */ static void rcu_wake_cpu(void *unused) { + trace_rcu_prep_idle("CPU awakened at GP end"); invoke_rcu_core(); } |