diff options
| author | Wang Tao | 2026-01-20 12:31:13 +0000 |
|---|---|---|
| committer | Sasha Levin | 2026-03-12 07:09:12 -0400 |
| commit | 6d4ad92278615de589f19734133e0fba42baa2be (patch) | |
| tree | f83ab1b09d75f8cfde73c074ed84f8115011f847 /kernel/sched/fair.c | |
| parent | f4994670aa669bca4049c634f1ee8f6d8ae9de6a (diff) | |
sched/eevdf: Update se->vprot in reweight_entity()
[ Upstream commit ff38424030f98976150e42ca35f4b00e6ab8fa23 ]
In the EEVDF framework with Run-to-Parity protection, `se->vprot` is an
independent variable defining the virtual protection timestamp.
When `reweight_entity()` is called (e.g., via nice/renice), it performs
the following actions to preserve Lag consistency:
1. Scales `se->vlag` based on the new weight.
2. Calls `place_entity()`, which recalculates `se->vruntime` based on
the new weight and scaled lag.
However, the current implementation fails to update `se->vprot`, leading
to mismatches between the task's actual runtime and its expected duration.
Fixes: 63304558ba5d ("sched/eevdf: Curb wakeup-preemption")
Suggested-by: Zhang Qiao <zhangqiao22@huawei.com>
Signed-off-by: Wang Tao <wangtao554@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Tested-by: Shubhang Kaushik <shubhang@os.amperecomputing.com>
Link: https://patch.msgid.link/20260120123113.3518950-1-wangtao554@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel/sched/fair.c')
| -rw-r--r-- | kernel/sched/fair.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 6f66d4f0540e..c8a6dac54e22 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3816,6 +3816,8 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, unsigned long weight) { bool curr = cfs_rq->curr == se; + bool rel_vprot = false; + u64 vprot; if (se->on_rq) { /* commit outstanding execution time */ @@ -3823,6 +3825,11 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, update_entity_lag(cfs_rq, se); se->deadline -= se->vruntime; se->rel_deadline = 1; + if (curr && protect_slice(se)) { + vprot = se->vprot - se->vruntime; + rel_vprot = true; + } + cfs_rq->nr_queued--; if (!curr) __dequeue_entity(cfs_rq, se); @@ -3838,6 +3845,9 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, if (se->rel_deadline) se->deadline = div_s64(se->deadline * se->load.weight, weight); + if (rel_vprot) + vprot = div_s64(vprot * se->load.weight, weight); + update_load_set(&se->load, weight); do { @@ -3849,6 +3859,8 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, enqueue_load_avg(cfs_rq, se); if (se->on_rq) { place_entity(cfs_rq, se, 0); + if (rel_vprot) + se->vprot = se->vruntime + vprot; update_load_add(&cfs_rq->load, se->load.weight); if (!curr) __enqueue_entity(cfs_rq, se); |