Re: [PATCH v2 1/7] sched/fair: Fix zero_vruntime tracking

[Peter Zijlstra <peterz@infradead.org>]

On Tue, Mar 31, 2026 at 02:20:35PM +0200, Peter Zijlstra wrote:

> WTF!?!


I'm thinking this might help... I'll try once I'm back home again.


diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index b24f40f05019..15bf45b6f912 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -902,6 +902,7 @@ static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
 void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 {
 	s64 left_vruntime = -1, zero_vruntime, right_vruntime = -1, left_deadline = -1, spread;
+	u64 avruntime;
 	struct sched_entity *last, *first, *root;
 	struct rq *rq = cpu_rq(cpu);
 	unsigned long flags;
@@ -925,6 +926,7 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 	if (last)
 		right_vruntime = last->vruntime;
 	zero_vruntime = cfs_rq->zero_vruntime;
+	avruntime = avg_vruntime(cfs_rq);
 	raw_spin_rq_unlock_irqrestore(rq, flags);
 
 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "left_deadline",
@@ -934,7 +936,7 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "zero_vruntime",
 			SPLIT_NS(zero_vruntime));
 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "avg_vruntime",
-			SPLIT_NS(avg_vruntime(cfs_rq)));
+			SPLIT_NS(avruntime));
 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "right_vruntime",
 			SPLIT_NS(right_vruntime));
 	spread = right_vruntime - left_vruntime;