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-rw-r--r--debian/patches-rt/0009-kthread-convert-worker-lock-to-raw-spinlock.patch203
1 files changed, 203 insertions, 0 deletions
diff --git a/debian/patches-rt/0009-kthread-convert-worker-lock-to-raw-spinlock.patch b/debian/patches-rt/0009-kthread-convert-worker-lock-to-raw-spinlock.patch
new file mode 100644
index 000000000..2d5f5508f
--- /dev/null
+++ b/debian/patches-rt/0009-kthread-convert-worker-lock-to-raw-spinlock.patch
@@ -0,0 +1,203 @@
+From 3384b42fd998f06c79b4536609c48e3147adb1eb Mon Sep 17 00:00:00 2001
+From: Julia Cartwright <julia@ni.com>
+Date: Fri, 28 Sep 2018 21:03:51 +0000
+Subject: [PATCH 009/347] kthread: convert worker lock to raw spinlock
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz
+
+In order to enable the queuing of kthread work items from hardirq
+context even when PREEMPT_RT_FULL is enabled, convert the worker
+spin_lock to a raw_spin_lock.
+
+This is only acceptable to do because the work performed under the lock
+is well-bounded and minimal.
+
+Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+Cc: Guenter Roeck <linux@roeck-us.net>
+Reported-and-tested-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
+Reported-by: Tim Sander <tim@krieglstein.org>
+Signed-off-by: Julia Cartwright <julia@ni.com>
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ include/linux/kthread.h | 2 +-
+ kernel/kthread.c | 42 ++++++++++++++++++++---------------------
+ 2 files changed, 22 insertions(+), 22 deletions(-)
+
+diff --git a/include/linux/kthread.h b/include/linux/kthread.h
+index 72308c38e06c..e0498e46d642 100644
+--- a/include/linux/kthread.h
++++ b/include/linux/kthread.h
+@@ -88,7 +88,7 @@ enum {
+
+ struct kthread_worker {
+ unsigned int flags;
+- spinlock_t lock;
++ raw_spinlock_t lock;
+ struct list_head work_list;
+ struct list_head delayed_work_list;
+ struct task_struct *task;
+diff --git a/kernel/kthread.c b/kernel/kthread.c
+index 9750f4f7f901..c8cf4731ced8 100644
+--- a/kernel/kthread.c
++++ b/kernel/kthread.c
+@@ -637,7 +637,7 @@ void __kthread_init_worker(struct kthread_worker *worker,
+ struct lock_class_key *key)
+ {
+ memset(worker, 0, sizeof(struct kthread_worker));
+- spin_lock_init(&worker->lock);
++ raw_spin_lock_init(&worker->lock);
+ lockdep_set_class_and_name(&worker->lock, key, name);
+ INIT_LIST_HEAD(&worker->work_list);
+ INIT_LIST_HEAD(&worker->delayed_work_list);
+@@ -679,21 +679,21 @@ int kthread_worker_fn(void *worker_ptr)
+
+ if (kthread_should_stop()) {
+ __set_current_state(TASK_RUNNING);
+- spin_lock_irq(&worker->lock);
++ raw_spin_lock_irq(&worker->lock);
+ worker->task = NULL;
+- spin_unlock_irq(&worker->lock);
++ raw_spin_unlock_irq(&worker->lock);
+ return 0;
+ }
+
+ work = NULL;
+- spin_lock_irq(&worker->lock);
++ raw_spin_lock_irq(&worker->lock);
+ if (!list_empty(&worker->work_list)) {
+ work = list_first_entry(&worker->work_list,
+ struct kthread_work, node);
+ list_del_init(&work->node);
+ }
+ worker->current_work = work;
+- spin_unlock_irq(&worker->lock);
++ raw_spin_unlock_irq(&worker->lock);
+
+ if (work) {
+ __set_current_state(TASK_RUNNING);
+@@ -850,12 +850,12 @@ bool kthread_queue_work(struct kthread_worker *worker,
+ bool ret = false;
+ unsigned long flags;
+
+- spin_lock_irqsave(&worker->lock, flags);
++ raw_spin_lock_irqsave(&worker->lock, flags);
+ if (!queuing_blocked(worker, work)) {
+ kthread_insert_work(worker, work, &worker->work_list);
+ ret = true;
+ }
+- spin_unlock_irqrestore(&worker->lock, flags);
++ raw_spin_unlock_irqrestore(&worker->lock, flags);
+ return ret;
+ }
+ EXPORT_SYMBOL_GPL(kthread_queue_work);
+@@ -881,7 +881,7 @@ void kthread_delayed_work_timer_fn(struct timer_list *t)
+ if (WARN_ON_ONCE(!worker))
+ return;
+
+- spin_lock(&worker->lock);
++ raw_spin_lock(&worker->lock);
+ /* Work must not be used with >1 worker, see kthread_queue_work(). */
+ WARN_ON_ONCE(work->worker != worker);
+
+@@ -891,7 +891,7 @@ void kthread_delayed_work_timer_fn(struct timer_list *t)
+ if (!work->canceling)
+ kthread_insert_work(worker, work, &worker->work_list);
+
+- spin_unlock(&worker->lock);
++ raw_spin_unlock(&worker->lock);
+ }
+ EXPORT_SYMBOL(kthread_delayed_work_timer_fn);
+
+@@ -947,14 +947,14 @@ bool kthread_queue_delayed_work(struct kthread_worker *worker,
+ unsigned long flags;
+ bool ret = false;
+
+- spin_lock_irqsave(&worker->lock, flags);
++ raw_spin_lock_irqsave(&worker->lock, flags);
+
+ if (!queuing_blocked(worker, work)) {
+ __kthread_queue_delayed_work(worker, dwork, delay);
+ ret = true;
+ }
+
+- spin_unlock_irqrestore(&worker->lock, flags);
++ raw_spin_unlock_irqrestore(&worker->lock, flags);
+ return ret;
+ }
+ EXPORT_SYMBOL_GPL(kthread_queue_delayed_work);
+@@ -990,7 +990,7 @@ void kthread_flush_work(struct kthread_work *work)
+ if (!worker)
+ return;
+
+- spin_lock_irq(&worker->lock);
++ raw_spin_lock_irq(&worker->lock);
+ /* Work must not be used with >1 worker, see kthread_queue_work(). */
+ WARN_ON_ONCE(work->worker != worker);
+
+@@ -1002,7 +1002,7 @@ void kthread_flush_work(struct kthread_work *work)
+ else
+ noop = true;
+
+- spin_unlock_irq(&worker->lock);
++ raw_spin_unlock_irq(&worker->lock);
+
+ if (!noop)
+ wait_for_completion(&fwork.done);
+@@ -1030,9 +1030,9 @@ static void kthread_cancel_delayed_work_timer(struct kthread_work *work,
+ * any queuing is blocked by setting the canceling counter.
+ */
+ work->canceling++;
+- spin_unlock_irqrestore(&worker->lock, *flags);
++ raw_spin_unlock_irqrestore(&worker->lock, *flags);
+ del_timer_sync(&dwork->timer);
+- spin_lock_irqsave(&worker->lock, *flags);
++ raw_spin_lock_irqsave(&worker->lock, *flags);
+ work->canceling--;
+ }
+
+@@ -1094,7 +1094,7 @@ bool kthread_mod_delayed_work(struct kthread_worker *worker,
+ unsigned long flags;
+ int ret = false;
+
+- spin_lock_irqsave(&worker->lock, flags);
++ raw_spin_lock_irqsave(&worker->lock, flags);
+
+ /* Do not bother with canceling when never queued. */
+ if (!work->worker)
+@@ -1123,7 +1123,7 @@ bool kthread_mod_delayed_work(struct kthread_worker *worker,
+ fast_queue:
+ __kthread_queue_delayed_work(worker, dwork, delay);
+ out:
+- spin_unlock_irqrestore(&worker->lock, flags);
++ raw_spin_unlock_irqrestore(&worker->lock, flags);
+ return ret;
+ }
+ EXPORT_SYMBOL_GPL(kthread_mod_delayed_work);
+@@ -1137,7 +1137,7 @@ static bool __kthread_cancel_work_sync(struct kthread_work *work, bool is_dwork)
+ if (!worker)
+ goto out;
+
+- spin_lock_irqsave(&worker->lock, flags);
++ raw_spin_lock_irqsave(&worker->lock, flags);
+ /* Work must not be used with >1 worker, see kthread_queue_work(). */
+ WARN_ON_ONCE(work->worker != worker);
+
+@@ -1154,13 +1154,13 @@ static bool __kthread_cancel_work_sync(struct kthread_work *work, bool is_dwork)
+ * In the meantime, block any queuing by setting the canceling counter.
+ */
+ work->canceling++;
+- spin_unlock_irqrestore(&worker->lock, flags);
++ raw_spin_unlock_irqrestore(&worker->lock, flags);
+ kthread_flush_work(work);
+- spin_lock_irqsave(&worker->lock, flags);
++ raw_spin_lock_irqsave(&worker->lock, flags);
+ work->canceling--;
+
+ out_fast:
+- spin_unlock_irqrestore(&worker->lock, flags);
++ raw_spin_unlock_irqrestore(&worker->lock, flags);
+ out:
+ return ret;
+ }
+--
+2.36.1
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-26 20:21:21 +0000