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release 6.15.3

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This commit is contained in:
Konstantin Demin
2025-06-19 18:06:35 +03:00
parent 43dc655d2e
commit 4cb7006cd5
67 changed files with 860 additions and 542 deletions
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62
debian/patches/patchset-pf/fixes/0023-sched-fair-Adhere-to-place_entity-constraints.patch vendored Normal file
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@@ -0,0 +1,62 @@
From e02cbdc12bf63da363d7e3391376819241d67fbe Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Tue, 28 Jan 2025 15:39:49 +0100
Subject: sched/fair: Adhere to place_entity() constraints
Mike reports that commit 6d71a9c61604 ("sched/fair: Fix EEVDF entity
placement bug causing scheduling lag") relies on commit 4423af84b297
("sched/fair: optimize the PLACE_LAG when se->vlag is zero") to not
trip a WARN in place_entity().
What happens is that the lag of the very last entity is 0 per
definition -- the average of one element matches the value of that
element. Therefore place_entity() will match the condition skipping
the lag adjustment:
if (sched_feat(PLACE_LAG) && cfs_rq->nr_queued && se->vlag) {
Without the 'se->vlag' condition -- it will attempt to adjust the zero
lag even though we're inserting into an empty tree.
Notably, we should have failed the 'cfs_rq->nr_queued' condition, but
don't because they didn't get updated.
Additionally, move update_load_add() after placement() as is
consistent with other place_entity() users -- this change is
non-functional, place_entity() does not use cfs_rq->load.
Fixes: 6d71a9c61604 ("sched/fair: Fix EEVDF entity placement bug causing scheduling lag")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/c216eb4ef0e0e0029c600aefc69d56681cee5581.camel@gmx.de
---
kernel/sched/fair.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3808,6 +3808,7 @@ static void reweight_entity(struct cfs_r
update_entity_lag(cfs_rq, se);
se->deadline -= se->vruntime;
se->rel_deadline = 1;
+ cfs_rq->nr_queued--;
if (!curr)
__dequeue_entity(cfs_rq, se);
update_load_sub(&cfs_rq->load, se->load.weight);
@@ -3834,10 +3835,11 @@ static void reweight_entity(struct cfs_r
enqueue_load_avg(cfs_rq, se);
if (se->on_rq) {
- update_load_add(&cfs_rq->load, se->load.weight);
place_entity(cfs_rq, se, 0);
+ update_load_add(&cfs_rq->load, se->load.weight);
if (!curr)
__enqueue_entity(cfs_rq, se);
+ cfs_rq->nr_queued++;
/*
* The entity's vruntime has been adjusted, so let's check