[PATCH] sched/fair: Fix math notation errors in avg_vruntime comment

From: Zhan Xusheng

Date: Wed Jan 14 2026 - 04:00:43 EST


The avg_vruntime comment contains a couple of mathematical notation
issues:

- The summation over w_i * (V - v_i) is written in an ambiguous form
- The delta term refers to v instead of v0, which is inconsistent
with the code and preceding explanation

Fix these to make the comment mathematically correct and consistent
with the implementation.

Signed-off-by: Zhan Xusheng <zhanxusheng@xxxxxxxxxx>
---
kernel/sched/fair.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e71302282671..36c6009a0df4 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -576,7 +576,7 @@ static inline s64 entity_key(struct cfs_rq *cfs_rq, struct sched_entity *se)
*
* \Sum lag_i = 0
* \Sum w_i * (V - v_i) = 0
- * \Sum w_i * V - w_i * v_i = 0
+ * \Sum (w_i * V - w_i * v_i) = 0
*
* From which we can solve an expression for V in v_i (which we have in
* se->vruntime):
@@ -611,7 +611,7 @@ static inline s64 entity_key(struct cfs_rq *cfs_rq, struct sched_entity *se)
* \Sum w_i := cfs_rq->avg_load
*
* Since zero_vruntime closely tracks the per-task service, these
- * deltas: (v_i - v), will be in the order of the maximal (virtual) lag
+ * deltas: (v_i - v0), will be in the order of the maximal (virtual) lag
* induced in the system due to quantisation.
*
* Also, we use scale_load_down() to reduce the size.
--
2.43.0