diff options
| author | Tejun Heo <tj@kernel.org> | 2024-06-25 15:29:58 -1000 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2024-07-04 15:59:52 +0200 |
| commit | d329605287020c3d1c3b0dadc63d8208e7251382 (patch) | |
| tree | 8e96bade108c8790c2f317621c616c085ad62c83 /kernel/sched/fair.c | |
| parent | 0ec208ce9834929769ace0e2a506106192d08069 (diff) | |
sched/fair: set_load_weight() must also call reweight_task() for SCHED_IDLE tasks
When a task's weight is being changed, set_load_weight() is called with
@update_load set. As weight changes aren't trivial for the fair class,
set_load_weight() calls fair.c::reweight_task() for fair class tasks.
However, set_load_weight() first tests task_has_idle_policy() on entry and
skips calling reweight_task() for SCHED_IDLE tasks. This is buggy as
SCHED_IDLE tasks are just fair tasks with a very low weight and they would
incorrectly skip load, vlag and position updates.
Fix it by updating reweight_task() to take struct load_weight as idle weight
can't be expressed with prio and making set_load_weight() call
reweight_task() for SCHED_IDLE tasks too when @update_load is set.
Fixes: 9059393e4ec1 ("sched/fair: Use reweight_entity() for set_user_nice()")
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org # v4.15+
Link: http://lkml.kernel.org/r/20240624102331.GI31592@noisy.programming.kicks-ass.net
Diffstat (limited to 'kernel/sched/fair.c')
| -rw-r--r-- | kernel/sched/fair.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 41b58387023d..f205e2482690 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3835,15 +3835,14 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, } } -void reweight_task(struct task_struct *p, int prio) +void reweight_task(struct task_struct *p, const struct load_weight *lw) { struct sched_entity *se = &p->se; struct cfs_rq *cfs_rq = cfs_rq_of(se); struct load_weight *load = &se->load; - unsigned long weight = scale_load(sched_prio_to_weight[prio]); - reweight_entity(cfs_rq, se, weight); - load->inv_weight = sched_prio_to_wmult[prio]; + reweight_entity(cfs_rq, se, lw->weight); + load->inv_weight = lw->inv_weight; } static inline int throttled_hierarchy(struct cfs_rq *cfs_rq); |