On Fri, 20 Mar 2020 00:22:25 +0100
Pavel Machek [off-list ref] wrote:

On Thu 2020-03-19 22:48:35, Pavel Machek wrote:

quoted

Hi!

Hi Pavel!

quoted

quoted

I'm pleased to announce the 4.19.106-rt44 stable release.


This release is just an update to the new stable 4.19.106 version
and no RT specific changes have been made.


You can get this release via the git tree at:

  git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

  branch: v4.19-rt
  Head SHA1: 0f2960c75dd68d339f0aff2935f51652b5625fbf  

This brought some problems for me. de0-nano board now fails to boot in
cca 50% of cases if I move these patches on top of -cip tree.

This is example of failed job:

https://lava.ciplatform.org/scheduler/job/13037

de0-nano is 32-bit arm, should be based on Altera SoCFPGA if I understand
things correctly.

"fc9f4631a290 irqwork: push most work into softirq context" touches
area of the panic above. I tried to revert it on top of the full
series, and tests passed twice so far...  

Test passed 7 times now. So yes, reverting this fixes de0-nano
boot. Any ideas what might be wrong?

I'll be running it few more times.

https://gitlab.com/cip-project/cip-kernel/linux-cip/pipelines/127953471

Looks like you are running this without PREEMPT_RT enabled.

Does this patch help?

-- Steve

diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 2940622da5b3..0ca75c77536b 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c

@@ -146,8 +146,9 @@ bool irq_work_needs_cpu(void)
 	raised = this_cpu_ptr(&raised_list);
 	lazy = this_cpu_ptr(&lazy_list);
 
-	if (llist_empty(raised) && llist_empty(lazy))
-		return false;
+	if (llist_empty(raised) || arch_irq_work_has_interrupt())
+		if (llist_empty(lazy))
+			return false;
 
 	/* All work should have been flushed before going offline */
 	WARN_ON_ONCE(cpu_is_offline(smp_processor_id()));