From: "tip-bot2 for Thomas Gleixner" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Mike Galbraith <efault@gmx.de>,
Thomas Gleixner <tglx@linutronix.de>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
x86@kernel.org, linux-kernel@vger.kernel.org, maz@kernel.org
Subject: [tip: irq/core] genirq: Move prio assignment into the newly created thread
Date: Fri, 17 Sep 2021 13:17:16 -0000 [thread overview]
Message-ID: <163188463696.25758.6952810439232292789.tip-bot2@tip-bot2> (raw)
In-Reply-To: <a23a826af7c108ea5651e73b8fbae5e653f16e86.camel@gmx.de>
The following commit has been merged into the irq/core branch of tip:
Commit-ID: e739f98b4b11337a4e3865364b8922a9e5ad32b6
Gitweb: https://git.kernel.org/tip/e739f98b4b11337a4e3865364b8922a9e5ad32b6
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 10 Nov 2020 12:38:48 +01:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Fri, 17 Sep 2021 15:08:22 +02:00
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
---
kernel/irq/manage.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index b392483..7405e38 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
next prev parent reply other threads:[~2021-09-17 13:17 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-21 12:53 [ANNOUNCE] v5.9.1-rt18 Sebastian Andrzej Siewior
2020-10-21 13:14 ` Sebastian Andrzej Siewior
2020-10-27 6:53 ` Fernando Lopez-Lezcano
2020-10-27 8:22 ` Sebastian Andrzej Siewior
2020-10-27 17:07 ` Fernando Lopez-Lezcano
2020-10-28 20:24 ` Sebastian Andrzej Siewior
2020-10-22 5:21 ` ltp or kvm triggerable lockdep alloc_pid() deadlock gripe Mike Galbraith
2020-10-22 16:44 ` Sebastian Andrzej Siewior
2020-10-22 5:28 ` kvm+nouveau induced lockdep gripe Mike Galbraith
2020-10-23 9:01 ` Sebastian Andrzej Siewior
2020-10-23 12:07 ` Mike Galbraith
[not found] ` <20201024022236.19608-1-hdanton@sina.com>
2020-10-24 3:38 ` Mike Galbraith
[not found] ` <20201024050000.8104-1-hdanton@sina.com>
2020-10-24 5:25 ` Mike Galbraith
[not found] ` <20201024094224.2804-1-hdanton@sina.com>
2020-10-26 17:26 ` Sebastian Andrzej Siewior
2020-10-26 17:31 ` Sebastian Andrzej Siewior
2020-10-26 19:15 ` Mike Galbraith
2020-10-26 19:53 ` Sebastian Andrzej Siewior
2020-10-27 6:03 ` Mike Galbraith
2020-10-27 9:00 ` Sebastian Andrzej Siewior
2020-10-27 9:49 ` Mike Galbraith
2020-10-27 10:14 ` Mike Galbraith
2020-10-27 10:18 ` Sebastian Andrzej Siewior
2020-10-27 11:13 ` Mike Galbraith
2021-09-17 13:17 ` tip-bot2 for Thomas Gleixner [this message]
2021-09-17 13:17 ` [tip: sched/core] kthread: Move prio/affinite change into the newly created thread tip-bot2 for Sebastian Andrzej Siewior
2021-09-17 18:36 ` tip-bot2 for Sebastian Andrzej Siewior
2021-10-05 14:12 ` tip-bot2 for Sebastian Andrzej Siewior
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