Linux v4.14.175-rt81-rc1

From: Tom Zanussi <[email protected]>

Dear RT Folks,

This is the RT stable review cycle of patch 4.14.175-rt81-rc1.

Please scream at me if I messed something up. Please test the patches too.

The -rc release will be uploaded to kernel.org and will be deleted when the final release is out. This is just a review release (or release candidate).

The pre-releases will not be pushed to the git repository, only the final release is.

If all goes well, this patch will be converted to the next main release on 2020-04-17.

To build 4.14.175-rt81-rc1 directly, the following patches should be applied:

https://www.kernel.org/pub/linux/kernel/v4.x/linux-4.14.tar.xz

https://www.kernel.org/pub/linux/kernel/v4.x/patch-4.14.175.xz

https://www.kernel.org/pub/linux/kernel/projects/rt/4.14/patch-4.14.175-rt81-rc1.patch.xz

You can also build from 4.14.175-rt80 by applying the incremental patch:

https://www.kernel.org/pub/linux/kernel/projects/rt/4.14/incr/patch-4.14.175-rt80-rt81-rc1.patch.xz

Enjoy,

-- Tom

Steven Rostedt (VMware) (1):
irq_work: Fix checking of IRQ_WORK_LAZY flag set on non PREEMPT_RT

Tom Zanussi (1):
Linux 4.14.175-rt81-rc1

 kernel/irq_work.c | 12 +++++++++---
 localversion-rt   |  2 +-
 2 files changed, 10 insertions(+), 4 deletions(-)

2.17.1

From: "Steven Rostedt (VMware)" <[email protected]>

v4.14.175-rt81-rc1 stable review patch.
If anyone has any objections, please let me know.

-----------

[ Upstream 4.19-rt commit a854c3525b7082189996a41c1dc057dcb138e305 ]

When CONFIG_PREEMPT_RT_FULL is not set, some of the checks for using lazy_list are not properly made as the IRQ_WORK_LAZY is not checked. There's two locations that need this update, so a use_lazy_list() helper function is added and used in both locations.

---
 kernel/irq_work.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

index 2899ba0d23d1..838b56cef5fe 100644
@@ -57,6 +57,12 @@ void __weak arch_irq_work_raise(void)
 	 */
 }
 
+static inline bool use_lazy_list(struct irq_work *work)
+{
+	return (IS_ENABLED(CONFIG_PREEMPT_RT_FULL) && !(work->flags & IRQ_WORK_HARD_IRQ))
+		|| (work->flags & IRQ_WORK_LAZY);
+}
+
 #ifdef CONFIG_SMP
 /*
  * Enqueue the irq_work @work on @cpu unless it's already pending

@@ -78,7 +84,7 @@ bool irq_work_queue_on(struct irq_work *work, int cpu)
 	if (!irq_work_claim(work))
 		return false;
 
-	if (IS_ENABLED(CONFIG_PREEMPT_RT_FULL) && !(work->flags & IRQ_WORK_HARD_IRQ))
+	if (use_lazy_list(work))
 		list = &per_cpu(lazy_list, cpu);
 	else
 		list = &per_cpu(raised_list, cpu);

@@ -95,7 +101,7 @@ EXPORT_SYMBOL_GPL(irq_work_queue_on);
 bool irq_work_queue(struct irq_work *work)
 {
 	struct llist_head *list;
-	bool lazy_work, realtime = IS_ENABLED(CONFIG_PREEMPT_RT_FULL);
+	bool lazy_work;
 
 	/* Only queue if not already pending */
 	if (!irq_work_claim(work))

@@ -106,7 +112,7 @@ bool irq_work_queue(struct irq_work *work)
 
 	lazy_work = work->flags & IRQ_WORK_LAZY;
 
-	if (lazy_work || (realtime && !(work->flags & IRQ_WORK_HARD_IRQ)))
+	if (use_lazy_list(work))
 		list = this_cpu_ptr(&lazy_list);
 	else
 		list = this_cpu_ptr(&raised_list);

2.17.1

From: Tom Zanussi <[email protected]>

v4.14.175-rt81-rc1 stable review patch.
If anyone has any objections, please let me know.

-----------

---
 localversion-rt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 5ba2c2091cf9..738174cbcc3e 100644
@@ -1 +1 @@
--rt80
+-rt81-rc1

2.17.1