diff options
Diffstat (limited to 'debian/patches-rt/0055-irq_work-Also-rcuwait-for-IRQ_WORK_HARD_IRQ-on-PREEM.patch')
| -rw-r--r-- | debian/patches-rt/0055-irq_work-Also-rcuwait-for-IRQ_WORK_HARD_IRQ-on-PREEM.patch | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/debian/patches-rt/0055-irq_work-Also-rcuwait-for-IRQ_WORK_HARD_IRQ-on-PREEM.patch b/debian/patches-rt/0055-irq_work-Also-rcuwait-for-IRQ_WORK_HARD_IRQ-on-PREEM.patch new file mode 100644 index 000000000..bed7de837 --- /dev/null +++ b/debian/patches-rt/0055-irq_work-Also-rcuwait-for-IRQ_WORK_HARD_IRQ-on-PREEM.patch @@ -0,0 +1,63 @@ +From eb1f04a88f1f21b5cc7c29127e10a4ce2e68dbad Mon Sep 17 00:00:00 2001 +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Wed, 6 Oct 2021 13:18:52 +0200 +Subject: [PATCH 055/158] irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on + PREEMPT_RT +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.15/older/patches-5.15.10-rt24.tar.xz + +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> +Link: https://lore.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 b48955e9c920..8cd11a223260 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 90b6b56f92e9..f7df715ec28e 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; +-- +2.33.1 + |