GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-06-25 08:02:56 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

rcu: add tracing for RCU's kthread run states.

Browse source 
Add tracing to help debugging situations when RCU's kthreads are not
running but are supposed to be.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit is contained in:
Paul E. McKenney 2011-03-29 17:48:28 -07:00 • committed by Paul E. McKenney
parent 0ac3d136b2
commit d71df90ead
4 changed files with 44 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

11
kernel/rcutree.c
View file

@ -91,8 +91,9 @@ EXPORT_SYMBOL_GPL(rcu_scheduler_active);
* handle all flavors of RCU.
*/
static DEFINE_PER_CPU(struct task_struct *, rcu_cpu_kthread_task);
DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_status);
static DEFINE_PER_CPU(wait_queue_head_t, rcu_cpu_wq);
static DEFINE_PER_CPU(char, rcu_cpu_has_work);
DEFINE_PER_CPU(char, rcu_cpu_has_work);
static char rcu_kthreads_spawnable;
static void rcu_node_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu);
@ -1563,11 +1564,13 @@ static int rcu_cpu_kthread(void *arg)
int cpu = (int)(long)arg;
unsigned long flags;
int spincnt = 0;
unsigned int *statusp = &per_cpu(rcu_cpu_kthread_status, cpu);
wait_queue_head_t *wqp = &per_cpu(rcu_cpu_wq, cpu);
char work;
char *workp = &per_cpu(rcu_cpu_has_work, cpu);
for (;;) {
*statusp = RCU_KTHREAD_WAITING;
wait_event_interruptible(*wqp,
*workp != 0 || kthread_should_stop());
local_bh_disable();
@ -1575,6 +1578,7 @@ static int rcu_cpu_kthread(void *arg)
local_bh_enable();
break;
}
*statusp = RCU_KTHREAD_RUNNING;
local_irq_save(flags);
work = *workp;
*workp = 0;
@ -1587,10 +1591,12 @@ static int rcu_cpu_kthread(void *arg)
else
spincnt = 0;
if (spincnt > 10) {
*statusp = RCU_KTHREAD_YIELDING;
rcu_yield(rcu_cpu_kthread_timer, (unsigned long)cpu);
spincnt = 0;
}
}
*statusp = RCU_KTHREAD_STOPPED;
return 0;
}
@ -1637,10 +1643,12 @@ static int rcu_node_kthread(void *arg)
struct task_struct *t;
for (;;) {
rnp->node_kthread_status = RCU_KTHREAD_WAITING;
wait_event_interruptible(rnp->node_wq, rnp->wakemask != 0 ||
kthread_should_stop());
if (kthread_should_stop())
break;
rnp->node_kthread_status = RCU_KTHREAD_RUNNING;
raw_spin_lock_irqsave(&rnp->lock, flags);
mask = rnp->wakemask;
rnp->wakemask = 0;
@ -1661,6 +1669,7 @@ static int rcu_node_kthread(void *arg)
preempt_enable();
}
}
rnp->node_kthread_status = RCU_KTHREAD_STOPPED;
return 0;
}