On Wed, 09 Oct 2024 10:30:28 -0700
Ankur Arora [off-list ref] wrote:

quoted

+++ b/kernel/trace/trace.c

@@ -2544,6 +2544,8 @@ unsigned int tracing_gen_ctx_irq_test(unsigned int irqs_status)
 		trace_flags |= TRACE_FLAG_NEED_RESCHED;
 	if (test_preempt_need_resched())
 		trace_flags |= TRACE_FLAG_PREEMPT_RESCHED;
+	if (tif_test_bit(TIF_NEED_RESCHED_LAZY))  

TIF_NEED_RESCHED_LAZY falls back to TIF_NEED_RESCHED without
CONFIG_ARCH_HAS_PREEMPT_LAZY. So, you might need to add an explicit
check for that as well.

With that,
 Reviewed-by: Ankur Arora [off-list ref]

Ankur

So this should be:

	if (IS_ENABLED(CONFIG_ARCH_HAS_PREEMPT_LAZY) &&
	    tif_test_bit(TIF_NEED_RESCHED_LAZY))

?

-- Steve

quoted

+		trace_flags |= TRACE_FLAG_NEED_RESCHED_LAZY;
 	return (trace_flags << 16) | (min_t(unsigned int, pc & 0xff, 0xf)) |
 		(min_t(unsigned int, migration_disable_value(), 0xf)) << 4;
 }

diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 829daa0764dd9..23ca2155306b1 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c

@@ -463,17 +463,29 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 		!IS_ENABLED(CONFIG_TRACE_IRQFLAGS_SUPPORT) ? 'X' :
 		'.';

-	switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
+	switch (entry->flags & (TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_NEED_RESCHED_LAZY |
 				TRACE_FLAG_PREEMPT_RESCHED)) {
+	case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_NEED_RESCHED_LAZY | TRACE_FLAG_PREEMPT_RESCHED:
+		need_resched = 'B';
+		break;
 	case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 		need_resched = 'N';
 		break;
+	case TRACE_FLAG_NEED_RESCHED_LAZY | TRACE_FLAG_PREEMPT_RESCHED:
+		need_resched = 'L';
+		break;
+	case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_NEED_RESCHED_LAZY:
+		need_resched = 'b';
+		break;
 	case TRACE_FLAG_NEED_RESCHED:
 		need_resched = 'n';
 		break;
 	case TRACE_FLAG_PREEMPT_RESCHED:
 		need_resched = 'p';
 		break;
+	case TRACE_FLAG_NEED_RESCHED_LAZY:
+		need_resched = 'l';
+		break;
 	default:
 		need_resched = '.';
 		break;