From: "tip-bot2 for Sebastian Andrzej Siewior" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: sched/core] irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on PREEMPT_RT
Date: Fri, 15 Oct 2021 09:44:54 -0000 [thread overview]
Message-ID: <163429109409.25758.10980405022488264190.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20211006111852.1514359-5-bigeasy@linutronix.de>
The following commit has been merged into the sched/core branch of tip:
Commit-ID: 09089db79859cbccccd8df95b034f36f7027efa6
Gitweb: https://git.kernel.org/tip/09089db79859cbccccd8df95b034f36f7027efa6
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
AuthorDate: Wed, 06 Oct 2021 13:18:52 +02:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Fri, 15 Oct 2021 11:25:18 +02:00
irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on PREEMPT_RT
On PREEMPT_RT most items are processed as LAZY via softirq context.
Avoid to spin-wait for them because irq_work_sync() could have higher
priority and not allow the irq-work to be completed.
Wait additionally for !IRQ_WORK_HARD_IRQ irq_work items on PREEMPT_RT.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211006111852.1514359-5-bigeasy@linutronix.de
---
include/linux/irq_work.h | 5 +++++
kernel/irq_work.c | 6 ++++--
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
index b48955e..8cd11a2 100644
--- a/include/linux/irq_work.h
+++ b/include/linux/irq_work.h
@@ -49,6 +49,11 @@ static inline bool irq_work_is_busy(struct irq_work *work)
return atomic_read(&work->node.a_flags) & IRQ_WORK_BUSY;
}
+static inline bool irq_work_is_hard(struct irq_work *work)
+{
+ return atomic_read(&work->node.a_flags) & IRQ_WORK_HARD_IRQ;
+}
+
bool irq_work_queue(struct irq_work *work);
bool irq_work_queue_on(struct irq_work *work, int cpu);
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 90b6b56..f7df715 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -217,7 +217,8 @@ void irq_work_single(void *arg)
*/
(void)atomic_cmpxchg(&work->node.a_flags, flags, flags & ~IRQ_WORK_BUSY);
- if (!arch_irq_work_has_interrupt())
+ if ((IS_ENABLED(CONFIG_PREEMPT_RT) && !irq_work_is_hard(work)) ||
+ !arch_irq_work_has_interrupt())
rcuwait_wake_up(&work->irqwait);
}
@@ -277,7 +278,8 @@ void irq_work_sync(struct irq_work *work)
lockdep_assert_irqs_enabled();
might_sleep();
- if (!arch_irq_work_has_interrupt()) {
+ if ((IS_ENABLED(CONFIG_PREEMPT_RT) && !irq_work_is_hard(work)) ||
+ !arch_irq_work_has_interrupt()) {
rcuwait_wait_event(&work->irqwait, !irq_work_is_busy(work),
TASK_UNINTERRUPTIBLE);
return;
prev parent reply other threads:[~2021-10-15 9:44 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-06 11:18 [PATCH v2 0/4] irq_work: PREEMPT_RT bits Sebastian Andrzej Siewior
2021-10-06 11:18 ` [PATCH v2 1/4] sched/rt: Annotate the RT balancing logic irqwork as IRQ_WORK_HARD_IRQ Sebastian Andrzej Siewior
2021-10-13 22:13 ` Steven Rostedt
2021-10-15 9:44 ` [tip: sched/core] " tip-bot2 for Sebastian Andrzej Siewior
2021-10-06 11:18 ` [PATCH v2 2/4] irq_work: Allow irq_work_sync() to sleep if irq_work() no IRQ support Sebastian Andrzej Siewior
2021-10-15 9:44 ` [tip: sched/core] " tip-bot2 for Sebastian Andrzej Siewior
2021-10-06 11:18 ` [PATCH v2 3/4] irq_work: Handle some irq_work in a per-CPU thread on PREEMPT_RT Sebastian Andrzej Siewior
2021-10-06 11:35 ` Sebastian Andrzej Siewior
2021-10-06 16:26 ` kernel test robot
2021-10-07 8:50 ` Peter Zijlstra
2021-10-07 9:08 ` Sebastian Andrzej Siewior
2021-10-07 9:26 ` [PATCH v3 " Sebastian Andrzej Siewior
2021-10-15 9:44 ` [tip: sched/core] " tip-bot2 for Sebastian Andrzej Siewior
2021-10-06 11:18 ` [PATCH v2 4/4] irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ " Sebastian Andrzej Siewior
2021-10-15 9:44 ` tip-bot2 for Sebastian Andrzej Siewior [this message]
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