[PATCH] rcu: Use IRQ_WORK_INIT_HARD for srcu's irq_work
Sebastian Andrzej Siewior <[email protected]>
| Newsgroups | org.kernel.vger.rcu,dev.linux.lists.linux-rt-devel |
|---|---|
| Message-ID | <[email protected]> |
The irq_work in srcu is used to schedule a delayed work. The work item
is not scheduled directly because it is not always possible wake a
thread directly.
On PREEMPT_RT the default irq_work is initialized with IRQ_WORK_LAZY and
is delayed to the irq_work thread. A system booted with the command line
"trace_event=…" will freeze during boot because the irq_work thread is
not yet deployed (and tracing uses synchronize_srcu() in
tp_rcu_cond_sync()).
The irq_work performs just a wakeup a thread, there is nothing wrong
with doing this from hardirq context on PREEMPT_RT.
Use IRQ_WORK_INIT_HARD for srcu's irq_work.
Fixes: 7c405fb3279b3 ("rcu: Use an intermediate irq_work to start process_srcu()")
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
---
kernel/rcu/srcutree.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index 7c2f7cc131f7a..b703233d4a63f 100644
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -218,7 +218,7 @@ static int init_srcu_struct_fields(struct srcu_struct *ssp, bool is_static)
mutex_init(&ssp->srcu_sup->srcu_barrier_mutex);
atomic_set(&ssp->srcu_sup->srcu_barrier_cpu_cnt, 0);
INIT_DELAYED_WORK(&ssp->srcu_sup->work, process_srcu);
- init_irq_work(&ssp->srcu_sup->irq_work, srcu_irq_work);
+ ssp->srcu_sup->irq_work = IRQ_WORK_INIT_HARD(srcu_irq_work);
ssp->srcu_sup->sda_is_static = is_static;
if (!is_static) {
ssp->sda = alloc_percpu(struct srcu_data);
--
2.55.0