diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2020-11-10 12:38:48 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-09-17 15:08:22 +0200 |
| commit | e739f98b4b11337a4e3865364b8922a9e5ad32b6 (patch) | |
| tree | 2ee755daa0014b41a0b33fc51121fb426dca8f4f /kernel/irq | |
| parent | e1a6af4b000c39148ab407362fcce3ab63b186f2 (diff) | |
genirq: Move prio assignment into the newly created thread
With enabled threaded interrupts the nouveau driver reported the
following:
| Chain exists of:
| &mm->mmap_lock#2 --> &device->mutex --> &cpuset_rwsem
|
| Possible unsafe locking scenario:
|
| CPU0 CPU1
| ---- ----
| lock(&cpuset_rwsem);
| lock(&device->mutex);
| lock(&cpuset_rwsem);
| lock(&mm->mmap_lock#2);
The device->mutex is nvkm_device::mutex.
Unblocking the lockchain at `cpuset_rwsem' is probably the easiest
thing to do. Move the priority assignment to the start of the newly
created thread.
Fixes: 710da3c8ea7df ("sched/core: Prevent race condition between cpuset and __sched_setscheduler()")
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bigeasy: Patch description]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/a23a826af7c108ea5651e73b8fbae5e653f16e86.camel@gmx.de
Diffstat (limited to 'kernel/irq')
| -rw-r--r-- | kernel/irq/manage.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index b39248325541..7405e384e5ed 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1259,6 +1259,8 @@ static int irq_thread(void *data) irqreturn_t (*handler_fn)(struct irq_desc *desc, struct irqaction *action); + sched_set_fifo(current); + if (force_irqthreads() && test_bit(IRQTF_FORCED_THREAD, &action->thread_flags)) handler_fn = irq_forced_thread_fn; @@ -1424,8 +1426,6 @@ setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary) if (IS_ERR(t)) return PTR_ERR(t); - sched_set_fifo(t); - /* * We keep the reference to the task struct even if * the thread dies to avoid that the interrupt code |