#include <linux/notifier.h>
#include <linux/rcupdate.h>
#include <linux/cpu.h>
+#include <linux/mutex.h>
/* Definition for rcupdate control block. */
-struct rcu_ctrlblk rcu_ctrlblk = {
+static struct rcu_ctrlblk rcu_ctrlblk = {
.cur = -300,
.completed = -300,
.lock = SPIN_LOCK_UNLOCKED,
.cpumask = CPU_MASK_NONE,
};
-struct rcu_ctrlblk rcu_bh_ctrlblk = {
+static struct rcu_ctrlblk rcu_bh_ctrlblk = {
.cur = -300,
.completed = -300,
.lock = SPIN_LOCK_UNLOCKED,
/* Fake initialization required by compiler */
static DEFINE_PER_CPU(struct tasklet_struct, rcu_tasklet) = {NULL};
-static int maxbatch = 10000;
+static int blimit = 10;
+static int qhimark = 10000;
+static int qlowmark = 100;
+#ifdef CONFIG_SMP
+static int rsinterval = 1000;
+#endif
+
+static atomic_t rcu_barrier_cpu_count;
+static DEFINE_MUTEX(rcu_barrier_mutex);
+static struct completion rcu_barrier_completion;
+
+#ifdef CONFIG_SMP
+static void force_quiescent_state(struct rcu_data *rdp,
+ struct rcu_ctrlblk *rcp)
+{
+ int cpu;
+ cpumask_t cpumask;
+ set_need_resched();
+ if (unlikely(rdp->qlen - rdp->last_rs_qlen > rsinterval)) {
+ rdp->last_rs_qlen = rdp->qlen;
+ /*
+ * Don't send IPI to itself. With irqs disabled,
+ * rdp->cpu is the current cpu.
+ */
+ cpumask = rcp->cpumask;
+ cpu_clear(rdp->cpu, cpumask);
+ for_each_cpu_mask(cpu, cpumask)
+ smp_send_reschedule(cpu);
+ }
+}
+#else
+static inline void force_quiescent_state(struct rcu_data *rdp,
+ struct rcu_ctrlblk *rcp)
+{
+ set_need_resched();
+}
+#endif
/**
* call_rcu - Queue an RCU callback for invocation after a grace period.
rdp = &__get_cpu_var(rcu_data);
*rdp->nxttail = head;
rdp->nxttail = &head->next;
-
- if (unlikely(++rdp->count > 10000))
- set_need_resched();
-
+ if (unlikely(++rdp->qlen > qhimark)) {
+ rdp->blimit = INT_MAX;
+ force_quiescent_state(rdp, &rcu_ctrlblk);
+ }
local_irq_restore(flags);
}
-static atomic_t rcu_barrier_cpu_count;
-static struct semaphore rcu_barrier_sema;
-static struct completion rcu_barrier_completion;
-
/**
* call_rcu_bh - Queue an RCU for invocation after a quicker grace period.
* @head: structure to be used for queueing the RCU updates.
rdp = &__get_cpu_var(rcu_bh_data);
*rdp->nxttail = head;
rdp->nxttail = &head->next;
- rdp->count++;
-/*
- * Should we directly call rcu_do_batch() here ?
- * if (unlikely(rdp->count > 10000))
- * rcu_do_batch(rdp);
- */
+
+ if (unlikely(++rdp->qlen > qhimark)) {
+ rdp->blimit = INT_MAX;
+ force_quiescent_state(rdp, &rcu_bh_ctrlblk);
+ }
+
local_irq_restore(flags);
}
void rcu_barrier(void)
{
BUG_ON(in_interrupt());
- /* Take cpucontrol semaphore to protect against CPU hotplug */
- down(&rcu_barrier_sema);
+ /* Take cpucontrol mutex to protect against CPU hotplug */
+ mutex_lock(&rcu_barrier_mutex);
init_completion(&rcu_barrier_completion);
atomic_set(&rcu_barrier_cpu_count, 0);
on_each_cpu(rcu_barrier_func, NULL, 0, 1);
wait_for_completion(&rcu_barrier_completion);
- up(&rcu_barrier_sema);
+ mutex_unlock(&rcu_barrier_mutex);
}
EXPORT_SYMBOL_GPL(rcu_barrier);
next = rdp->donelist = list->next;
list->func(list);
list = next;
- rdp->count--;
- if (++count >= maxbatch)
+ rdp->qlen--;
+ if (++count >= rdp->blimit)
break;
}
+ if (rdp->blimit == INT_MAX && rdp->qlen <= qlowmark)
+ rdp->blimit = blimit;
if (!rdp->donelist)
rdp->donetail = &rdp->donelist;
else
rdp->curtail = &rdp->curlist;
}
- local_irq_disable();
if (rdp->nxtlist && !rdp->curlist) {
+ local_irq_disable();
rdp->curlist = rdp->nxtlist;
rdp->curtail = rdp->nxttail;
rdp->nxtlist = NULL;
rcu_start_batch(rcp);
spin_unlock(&rcp->lock);
}
- } else {
- local_irq_enable();
}
+
rcu_check_quiescent_state(rcp, rdp);
if (rdp->donelist)
rcu_do_batch(rdp);
rdp->quiescbatch = rcp->completed;
rdp->qs_pending = 0;
rdp->cpu = cpu;
+ rdp->blimit = blimit;
}
static void __devinit rcu_online_cpu(int cpu)
*/
void __init rcu_init(void)
{
- sema_init(&rcu_barrier_sema, 1);
rcu_cpu_notify(&rcu_nb, CPU_UP_PREPARE,
(void *)(long)smp_processor_id());
/* Register notifier for non-boot CPUs */
synchronize_rcu();
}
-module_param(maxbatch, int, 0);
+module_param(blimit, int, 0);
+module_param(qhimark, int, 0);
+module_param(qlowmark, int, 0);
+#ifdef CONFIG_SMP
+module_param(rsinterval, int, 0);
+#endif
EXPORT_SYMBOL_GPL(rcu_batches_completed);
-EXPORT_SYMBOL(call_rcu); /* WARNING: GPL-only in April 2006. */
-EXPORT_SYMBOL(call_rcu_bh); /* WARNING: GPL-only in April 2006. */
+EXPORT_SYMBOL_GPL_FUTURE(call_rcu); /* WARNING: GPL-only in April 2006. */
+EXPORT_SYMBOL_GPL_FUTURE(call_rcu_bh); /* WARNING: GPL-only in April 2006. */
EXPORT_SYMBOL_GPL(synchronize_rcu);
-EXPORT_SYMBOL(synchronize_kernel); /* WARNING: GPL-only in April 2006. */
+EXPORT_SYMBOL_GPL_FUTURE(synchronize_kernel); /* WARNING: GPL-only in April 2006. */