Adding debian version 6.6.15-2.debian/6.6.15-2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 47 insertions, 0 deletions

diff --git a/debian/patches-rt/0003-time-Allow-to-preempt-after-a-callback.patch b/debian/patches-rt/0003-time-Allow-to-preempt-after-a-callback.patch
new file mode 100644
index 0000000000..7ede7d6ae5
--- /dev/null
+++ b/debian/patches-rt/0003-time-Allow-to-preempt-after-a-callback.patch
@@ -0,0 +1,47 @@
+From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+Date: Fri, 4 Aug 2023 13:30:39 +0200
+Subject: [PATCH 3/3] time: Allow to preempt after a callback.
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz
+
+The TIMER_SOFTIRQ handler invokes timer callbacks of the expired timers.
+Before each invocation the timer_base::lock is dropped. The only lock
+that is still held is the timer_base::expiry_lock and the per-CPU
+bh-lock as part of local_bh_disable(). The former is released as part
+of lock up prevention if the timer is preempted by the caller which is
+waiting for its completion.
+
+Both locks are already released as part of timer_sync_wait_running().
+This can be extended by also releasing in bh-lock. The timer core does
+not rely on any state that is serialized by the bh-lock. The timer
+callback expects the bh-state to be serialized by the lock but there is
+no need to keep state synchronized while invoking multiple callbacks.
+
+Preempt handling softirqs and release all locks after a timer invocation
+if the current has inherited priority.
+
+Link: https://lore.kernel.org/r/20230804113039.419794-4-bigeasy@linutronix.de
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ kernel/time/timer.c |    9 ++++++++-
+ 1 file changed, 8 insertions(+), 1 deletion(-)
+
+--- a/kernel/time/timer.c
++++ b/kernel/time/timer.c
+@@ -1470,9 +1470,16 @@ static inline void timer_base_unlock_exp
+  */
+ static void timer_sync_wait_running(struct timer_base *base)
+ {
+-	if (atomic_read(&base->timer_waiters)) {
++	bool need_preempt;
++
++	need_preempt = task_is_pi_boosted(current);
++	if (need_preempt || atomic_read(&base->timer_waiters)) {
+ 		raw_spin_unlock_irq(&base->lock);
+ 		spin_unlock(&base->expiry_lock);
++
++		if (need_preempt)
++			softirq_preempt();
++
+ 		spin_lock(&base->expiry_lock);
+ 		raw_spin_lock_irq(&base->lock);
+ 	}