EXPORT_SYMBOL_GPL(rcu_note_context_switch);
DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = {
- .dynticks_nesting = LLONG_MAX / 2,
+ .dynticks_nesting = DYNTICK_TASK_NESTING,
.dynticks = ATOMIC_INIT(1),
};
* we really have entered idle, and must do the appropriate accounting.
* The caller must have disabled interrupts.
*/
-static void rcu_idle_enter_common(struct rcu_dynticks *rdtp)
+static void rcu_idle_enter_common(struct rcu_dynticks *rdtp, long long oldval)
{
- if (rdtp->dynticks_nesting) {
- trace_rcu_dyntick("--=", rdtp->dynticks_nesting);
- return;
- }
- trace_rcu_dyntick("Start", rdtp->dynticks_nesting);
- if (!idle_cpu(smp_processor_id())) {
- WARN_ON_ONCE(1); /* must be idle task! */
- trace_rcu_dyntick("Error on entry: not idle task",
- rdtp->dynticks_nesting);
+ trace_rcu_dyntick("Start", oldval, 0);
+ if (!is_idle_task(current)) {
+ struct task_struct *idle = idle_task(smp_processor_id());
+
+ trace_rcu_dyntick("Error on entry: not idle task", oldval, 0);
ftrace_dump(DUMP_ALL);
+ WARN_ONCE(1, "Current pid: %d comm: %s / Idle pid: %d comm: %s",
+ current->pid, current->comm,
+ idle->pid, idle->comm); /* must be idle task! */
}
+ rcu_prepare_for_idle(smp_processor_id());
/* CPUs seeing atomic_inc() must see prior RCU read-side crit sects */
smp_mb__before_atomic_inc(); /* See above. */
atomic_inc(&rdtp->dynticks);
void rcu_idle_enter(void)
{
unsigned long flags;
+ long long oldval;
struct rcu_dynticks *rdtp;
local_irq_save(flags);
rdtp = &__get_cpu_var(rcu_dynticks);
+ oldval = rdtp->dynticks_nesting;
rdtp->dynticks_nesting = 0;
- rcu_idle_enter_common(rdtp);
+ rcu_idle_enter_common(rdtp, oldval);
local_irq_restore(flags);
}
void rcu_irq_exit(void)
{
unsigned long flags;
+ long long oldval;
struct rcu_dynticks *rdtp;
local_irq_save(flags);
rdtp = &__get_cpu_var(rcu_dynticks);
+ oldval = rdtp->dynticks_nesting;
rdtp->dynticks_nesting--;
WARN_ON_ONCE(rdtp->dynticks_nesting < 0);
- rcu_idle_enter_common(rdtp);
+ if (rdtp->dynticks_nesting)
+ trace_rcu_dyntick("--=", oldval, rdtp->dynticks_nesting);
+ else
+ rcu_idle_enter_common(rdtp, oldval);
local_irq_restore(flags);
}
*/
static void rcu_idle_exit_common(struct rcu_dynticks *rdtp, long long oldval)
{
- if (oldval) {
- trace_rcu_dyntick("++=", rdtp->dynticks_nesting);
- return;
- }
smp_mb__before_atomic_inc(); /* Force ordering w/previous sojourn. */
atomic_inc(&rdtp->dynticks);
/* CPUs seeing atomic_inc() must see later RCU read-side crit sects */
smp_mb__after_atomic_inc(); /* See above. */
WARN_ON_ONCE(!(atomic_read(&rdtp->dynticks) & 0x1));
- trace_rcu_dyntick("End", oldval);
- if (!idle_cpu(smp_processor_id())) {
- WARN_ON_ONCE(1); /* must be idle task! */
- trace_rcu_dyntick("Error on exit: not idle task", oldval);
+ rcu_cleanup_after_idle(smp_processor_id());
+ trace_rcu_dyntick("End", oldval, rdtp->dynticks_nesting);
+ if (!is_idle_task(current)) {
+ struct task_struct *idle = idle_task(smp_processor_id());
+
+ trace_rcu_dyntick("Error on exit: not idle task",
+ oldval, rdtp->dynticks_nesting);
ftrace_dump(DUMP_ALL);
+ WARN_ONCE(1, "Current pid: %d comm: %s / Idle pid: %d comm: %s",
+ current->pid, current->comm,
+ idle->pid, idle->comm); /* must be idle task! */
}
}
* Exit idle mode, in other words, -enter- the mode in which RCU
* read-side critical sections can occur.
*
- * We crowbar the ->dynticks_nesting field to LLONG_MAX/2 to allow for
- * the possibility of usermode upcalls messing up our count
+ * We crowbar the ->dynticks_nesting field to DYNTICK_TASK_NESTING to
+ * allow for the possibility of usermode upcalls messing up our count
* of interrupt nesting level during the busy period that is just
* now starting.
*/
rdtp = &__get_cpu_var(rcu_dynticks);
oldval = rdtp->dynticks_nesting;
WARN_ON_ONCE(oldval != 0);
- rdtp->dynticks_nesting = LLONG_MAX / 2;
+ rdtp->dynticks_nesting = DYNTICK_TASK_NESTING;
rcu_idle_exit_common(rdtp, oldval);
local_irq_restore(flags);
}
oldval = rdtp->dynticks_nesting;
rdtp->dynticks_nesting++;
WARN_ON_ONCE(rdtp->dynticks_nesting == 0);
- rcu_idle_exit_common(rdtp, oldval);
+ if (oldval)
+ trace_rcu_dyntick("++=", oldval, rdtp->dynticks_nesting);
+ else
+ rcu_idle_exit_common(rdtp, oldval);
local_irq_restore(flags);
}
* rcu_is_cpu_idle - see if RCU thinks that the current CPU is idle
*
* If the current CPU is in its idle loop and is neither in an interrupt
- * or NMI handler, return true. The caller must have at least disabled
- * preemption.
+ * or NMI handler, return true.
*/
int rcu_is_cpu_idle(void)
{
- return (atomic_read(&__get_cpu_var(rcu_dynticks).dynticks) & 0x1) == 0;
+ int ret;
+
+ preempt_disable();
+ ret = (atomic_read(&__get_cpu_var(rcu_dynticks).dynticks) & 0x1) == 0;
+ preempt_enable();
+ return ret;
}
+EXPORT_SYMBOL(rcu_is_cpu_idle);
#endif /* #ifdef CONFIG_PROVE_RCU */
static int dyntick_save_progress_counter(struct rcu_data *rdp)
{
rdp->dynticks_snap = atomic_add_return(0, &rdp->dynticks->dynticks);
- return 0;
+ return (rdp->dynticks_snap & 0x1) == 0;
}
/*
#endif /* #ifdef CONFIG_SMP */
-int rcu_cpu_stall_suppress __read_mostly;
-
static void record_gp_stall_check_time(struct rcu_state *rsp)
{
rsp->gp_start = jiffies;
else
raw_spin_unlock_irqrestore(&rnp->lock, flags);
if (need_report & RCU_OFL_TASKS_EXP_GP)
- rcu_report_exp_rnp(rsp, rnp);
+ rcu_report_exp_rnp(rsp, rnp, true);
rcu_node_kthread_setaffinity(rnp, -1);
}
/* If no callbacks are ready, just return.*/
if (!cpu_has_callbacks_ready_to_invoke(rdp)) {
trace_rcu_batch_start(rsp->name, 0, 0);
- trace_rcu_batch_end(rsp->name, 0);
+ trace_rcu_batch_end(rsp->name, 0, !!ACCESS_ONCE(rdp->nxtlist),
+ need_resched(), is_idle_task(current),
+ rcu_is_callbacks_kthread());
return;
}
debug_rcu_head_unqueue(list);
__rcu_reclaim(rsp->name, list);
list = next;
- if (++count >= bl)
+ /* Stop only if limit reached and CPU has something to do. */
+ if (++count >= bl &&
+ (need_resched() ||
+ (!is_idle_task(current) && !rcu_is_callbacks_kthread())))
break;
}
local_irq_save(flags);
- trace_rcu_batch_end(rsp->name, count);
+ trace_rcu_batch_end(rsp->name, count, !!list, need_resched(),
+ is_idle_task(current),
+ rcu_is_callbacks_kthread());
/* Update count, and requeue any remaining callbacks. */
rdp->qlen -= count;
* by the current CPU, even if none need be done immediately, returning
* 1 if so.
*/
-static int rcu_needs_cpu_quick_check(int cpu)
+static int rcu_cpu_has_callbacks(int cpu)
{
/* RCU callbacks either ready or pending? */
return per_cpu(rcu_sched_data, cpu).nxtlist ||
rdp->nxttail[i] = &rdp->nxtlist;
rdp->qlen = 0;
rdp->dynticks = &per_cpu(rcu_dynticks, cpu);
- WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != LLONG_MAX / 2);
+ WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != DYNTICK_TASK_NESTING);
WARN_ON_ONCE(atomic_read(&rdp->dynticks->dynticks) != 1);
rdp->cpu = cpu;
rdp->rsp = rsp;
rdp->qlen_last_fqs_check = 0;
rdp->n_force_qs_snap = rsp->n_force_qs;
rdp->blimit = blimit;
- WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != LLONG_MAX / 2);
- WARN_ON_ONCE((atomic_read(&rdp->dynticks->dynticks) & 0x1) != 1);
+ rdp->dynticks->dynticks_nesting = DYNTICK_TASK_NESTING;
+ atomic_set(&rdp->dynticks->dynticks,
+ (atomic_read(&rdp->dynticks->dynticks) & ~0x1) + 1);
+ rcu_prepare_for_idle_init(cpu);
raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
/*
rcu_send_cbs_to_online(&rcu_bh_state);
rcu_send_cbs_to_online(&rcu_sched_state);
rcu_preempt_send_cbs_to_online();
+ rcu_cleanup_after_idle(cpu);
break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
projects / platform / adaptation / renesas_rcar / renesas_kernel.git / blobdiff