diff options
Diffstat (limited to 'kernel/rcutree_plugin.h')
| -rw-r--r-- | kernel/rcutree_plugin.h | 29 |
1 files changed, 21 insertions, 8 deletions
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index d084ae3f281..71bd7337d0c 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -28,6 +28,7 @@ #include <linux/gfp.h> #include <linux/oom.h> #include <linux/smpboot.h> +#include <linux/tick.h> #define RCU_KTHREAD_PRIO 1 @@ -2052,7 +2053,7 @@ static void rcu_init_one_nocb(struct rcu_node *rnp) } /* Is the specified CPU a no-CPUs CPU? */ -static bool is_nocb_cpu(int cpu) +bool rcu_is_nocb_cpu(int cpu) { if (have_rcu_nocb_mask) return cpumask_test_cpu(cpu, rcu_nocb_mask); @@ -2110,7 +2111,7 @@ static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp, bool lazy) { - if (!is_nocb_cpu(rdp->cpu)) + if (!rcu_is_nocb_cpu(rdp->cpu)) return 0; __call_rcu_nocb_enqueue(rdp, rhp, &rhp->next, 1, lazy); if (__is_kfree_rcu_offset((unsigned long)rhp->func)) @@ -2134,7 +2135,7 @@ static bool __maybe_unused rcu_nocb_adopt_orphan_cbs(struct rcu_state *rsp, long qll = rsp->qlen_lazy; /* If this is not a no-CBs CPU, tell the caller to do it the old way. */ - if (!is_nocb_cpu(smp_processor_id())) + if (!rcu_is_nocb_cpu(smp_processor_id())) return 0; rsp->qlen = 0; rsp->qlen_lazy = 0; @@ -2306,11 +2307,6 @@ static void rcu_init_one_nocb(struct rcu_node *rnp) { } -static bool is_nocb_cpu(int cpu) -{ - return false; -} - static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp, bool lazy) { @@ -2337,3 +2333,20 @@ static bool init_nocb_callback_list(struct rcu_data *rdp) } #endif /* #else #ifdef CONFIG_RCU_NOCB_CPU */ + +/* + * An adaptive-ticks CPU can potentially execute in kernel mode for an + * arbitrarily long period of time with the scheduling-clock tick turned + * off. RCU will be paying attention to this CPU because it is in the + * kernel, but the CPU cannot be guaranteed to be executing the RCU state + * machine because the scheduling-clock tick has been disabled. Therefore, + * if an adaptive-ticks CPU is failing to respond to the current grace + * period and has not be idle from an RCU perspective, kick it. + */ +static void rcu_kick_nohz_cpu(int cpu) +{ +#ifdef CONFIG_NO_HZ_FULL + if (tick_nohz_full_cpu(cpu)) + smp_send_reschedule(cpu); +#endif /* #ifdef CONFIG_NO_HZ_FULL */ +} |