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Move the drain into the core sched_ext implementation first so the subsequent behavioral changes can be reviewed separately. No functional change. Signed-off-by: Andrea Righi --- kernel/sched/ext/ext.c | 49 ++++++++++++++++++++++++++++++++++++++++++ kernel/sched/ext/sub.c | 45 -------------------------------------- kernel/sched/ext/sub.h | 2 -- 3 files changed, 49 insertions(+), 47 deletions(-) diff --git a/kernel/sched/ext/ext.c b/kernel/sched/ext/ext.c index 307d2080b967a..967bf31a32754 100644 --- a/kernel/sched/ext/ext.c +++ b/kernel/sched/ext/ext.c @@ -4674,6 +4674,55 @@ static void process_deferred_reenq_users(struct rq *rq) } } +#ifdef CONFIG_EXT_SUB_SCHED +/* + * Drain @rq->scx.reject_dsq, reenqueueing each task so the BPF re-decides + * from p->scx.reenq_reason_*. + * + * A task can be re-rejected repeatedly. The reenqueue is bounded per task in + * scx_do_enqueue_task(), which ejects the owning sub past SCX_REENQ_MAX_REPEAT. + * Rejection can't happen for root. + */ +static void scx_reenq_reject(struct rq *rq) +{ + LIST_HEAD(tasks); + struct task_struct *p, *n; + + lockdep_assert_rq_held(rq); + + if (!scx_has_subs() || list_empty(&rq->scx.reject_dsq.list)) + return; + + /* + * Move to a private list so a task re-rejected by the + * scx_do_enqueue_task() below isn't revisited this round. + */ + list_for_each_entry_safe(p, n, &rq->scx.reject_dsq.list, scx.dsq_list.node) { + /* migration_pending tasks should have bypassed to local DSQ */ + if (WARN_ON_ONCE(p->migration_pending)) + continue; + + scx_dispatch_dequeue(rq, p); + + if (WARN_ON_ONCE(p->scx.flags & SCX_TASK_REENQ_REASON_MASK)) + p->scx.flags &= ~SCX_TASK_REENQ_REASON_MASK; + p->scx.flags |= SCX_TASK_REENQ_CAP; + + list_add_tail(&p->scx.dsq_list.node, &tasks); + } + + list_for_each_entry_safe(p, n, &tasks, scx.dsq_list.node) { + list_del_init(&p->scx.dsq_list.node); + + scx_do_enqueue_task(rq, p, SCX_ENQ_REENQ, -1); + + p->scx.flags &= ~SCX_TASK_REENQ_REASON_MASK; + } +} +#else +static void scx_reenq_reject(struct rq *rq) {} +#endif + static void run_deferred(struct rq *rq) { process_ddsp_deferred_locals(rq); diff --git a/kernel/sched/ext/sub.c b/kernel/sched/ext/sub.c index c3955c8163a03..a73593e828267 100644 --- a/kernel/sched/ext/sub.c +++ b/kernel/sched/ext/sub.c @@ -774,51 +774,6 @@ bool scx_task_reenq_on_cap_revoke(struct rq *rq, struct task_struct *p) return true; } -/* - * Drain @rq->scx.reject_dsq, reenqueueing each task so the BPF re-decides - * from p->scx.reenq_reason_*. - * - * A task can be re-rejected repeatedly. The reenqueue is bounded per task in - * scx_do_enqueue_task(), which ejects the owning sub past SCX_REENQ_MAX_REPEAT. - * Rejection can't happen for root. - */ -void scx_reenq_reject(struct rq *rq) -{ - LIST_HEAD(tasks); - struct task_struct *p, *n; - - lockdep_assert_rq_held(rq); - - if (!scx_has_subs() || list_empty(&rq->scx.reject_dsq.list)) - return; - - /* - * Move to a private list so a task re-rejected by the - * scx_do_enqueue_task() below isn't revisited this round. - */ - list_for_each_entry_safe(p, n, &rq->scx.reject_dsq.list, scx.dsq_list.node) { - /* migration_pending tasks should have bypassed to local DSQ */ - if (WARN_ON_ONCE(p->migration_pending)) - continue; - - scx_dispatch_dequeue(rq, p); - - if (WARN_ON_ONCE(p->scx.flags & SCX_TASK_REENQ_REASON_MASK)) - p->scx.flags &= ~SCX_TASK_REENQ_REASON_MASK; - p->scx.flags |= SCX_TASK_REENQ_CAP; - - list_add_tail(&p->scx.dsq_list.node, &tasks); - } - - list_for_each_entry_safe(p, n, &tasks, scx.dsq_list.node) { - list_del_init(&p->scx.dsq_list.node); - - scx_do_enqueue_task(rq, p, SCX_ENQ_REENQ, -1); - - p->scx.flags &= ~SCX_TASK_REENQ_REASON_MASK; - } -} - /* record a caps change, see struct scx_caps_updated */ static void caps_updated_record(struct scx_pshard *ps, const struct scx_cmask *cids, u64 caps, struct list_head *to_deliver) diff --git a/kernel/sched/ext/sub.h b/kernel/sched/ext/sub.h index f7bcdfda8dd85..8f2425bdb9530 100644 --- a/kernel/sched/ext/sub.h +++ b/kernel/sched/ext/sub.h @@ -37,7 +37,6 @@ void scx_discard_stale_ecaps_syncs(void); struct scx_dispatch_q *scx_resolve_local_dsq(struct scx_sched *sch, struct rq *rq, struct task_struct *p, u64 *enq_flags); bool scx_task_reenq_on_cap_revoke(struct rq *rq, struct task_struct *p); -void scx_reenq_reject(struct rq *rq); void scx_rescue_charge(struct rq *rq, s64 delta_exec); void scx_rescue_end(struct rq *rq); bool scx_rescue_keep(struct rq *rq, struct task_struct *p); @@ -93,7 +92,6 @@ static inline void scx_discard_ecaps_to_sync(s32 cpu, struct scx_sched_pcpu *pcp static inline void scx_discard_stale_ecaps_syncs(void) {} static inline struct scx_dispatch_q *scx_resolve_local_dsq(struct scx_sched *sch, struct rq *rq, struct task_struct *p, u64 *enq_flags) { return &rq->scx.local_dsq; } static inline bool scx_task_reenq_on_cap_revoke(struct rq *rq, struct task_struct *p) { return false; } -static inline void scx_reenq_reject(struct rq *rq) {} static inline void scx_rescue_charge(struct rq *rq, s64 delta_exec) {} static inline void scx_rescue_end(struct rq *rq) {} static inline bool scx_rescue_keep(struct rq *rq, struct task_struct *p) { return false; } -- 2.55.0