When initializing p->scx.weight, scx_ops_enable_task() wasn't considering whether the task is SCHED_IDLE. Update it to use WEIGHT_IDLEPRIO as the source weight for SCHED_IDLE tasks. This leaves reweight_task_scx() the sole user of set_task_scx_weight(). Open code it. @weight is going to be provided by sched core in the future anyway. Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> Cc: David Vernet <void@xxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> --- This is a related fix for sched_ext. Thanks. kernel/sched/ext.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -3237,22 +3237,23 @@ static int scx_ops_init_task(struct task return 0; } -static void set_task_scx_weight(struct task_struct *p) -{ - u32 weight = sched_prio_to_weight[p->static_prio - MAX_RT_PRIO]; - - p->scx.weight = sched_weight_to_cgroup(weight); -} - static void scx_ops_enable_task(struct task_struct *p) { + u32 weight; + lockdep_assert_rq_held(task_rq(p)); /* * Set the weight before calling ops.enable() so that the scheduler * doesn't see a stale value if they inspect the task struct. */ - set_task_scx_weight(p); + if (task_has_idle_policy(p)) + weight = WEIGHT_IDLEPRIO; + else + weight = sched_prio_to_weight[p->static_prio - MAX_RT_PRIO]; + + p->scx.weight = sched_weight_to_cgroup(weight); + if (SCX_HAS_OP(enable)) SCX_CALL_OP_TASK(SCX_KF_REST, enable, p); scx_set_task_state(p, SCX_TASK_ENABLED); @@ -3405,9 +3406,11 @@ void sched_ext_free(struct task_struct * static void reweight_task_scx(struct rq *rq, struct task_struct *p, int newprio) { + unsigned long weight = sched_prio_to_weight[newprio]; + lockdep_assert_rq_held(task_rq(p)); - set_task_scx_weight(p); + p->scx.weight = sched_weight_to_cgroup(weight); if (SCX_HAS_OP(set_weight)) SCX_CALL_OP_TASK(SCX_KF_REST, set_weight, p, p->scx.weight); }