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Introduce scx_allow_proxy_exec(), scx_proxy_donor_start() and scx_proxy_resolved(), and add their call sites in __schedule(). The implementations are empty here and are filled in by the sched_ext changes that follow, so that all the sched core changes needed by proxy execution stay together in the preparatory patches. SCHED_PROXY_EXEC still depends on !SCHED_CLASS_EXT, so the new hooks are inert: they are compiled out with CONFIG_SCHED_CLASS_EXT=n and unreachable otherwise. This is a preparatory change to support proxy execution with sched_ext. No functional change. Signed-off-by: Andrea Righi --- kernel/sched/core.c | 12 +++++++----- kernel/sched/ext/ext.c | 13 +++++++++++++ kernel/sched/ext/ext.h | 6 ++++++ 3 files changed, 26 insertions(+), 5 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index fe142e3bb78c8..08b4245a8f6b0 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7156,13 +7156,12 @@ static void __sched notrace __schedule(int sched_mode) } } else if (!preempt && prev_state) { /* - * We pass task_is_blocked() as the should_block arg - * in order to keep mutex-blocked tasks on the runqueue - * for slection with proxy-exec (without proxy-exec - * task_is_blocked() will always be false). + * Keep mutex-blocked tasks on the runqueue for proxy execution + * only when their scheduling class allows it. Without proxy + * execution, task_is_blocked() always returns false. */ try_to_block_task(rq, prev, &prev_state, - !task_is_blocked(prev)); + !task_is_blocked(prev) || !scx_allow_proxy_exec(prev)); switch_count = &prev->nvcsw; } @@ -7183,6 +7182,7 @@ static void __sched notrace __schedule(int sched_mode) } if (next == rq->idle) { zap_balance_callbacks(rq); + scx_proxy_resolved(rq); goto keep_resched; } } @@ -7203,6 +7203,8 @@ static void __sched notrace __schedule(int sched_mode) donor->sched_class->put_prev_task(rq, donor, donor); donor->sched_class->set_next_task(rq, donor, true); } + scx_proxy_donor_start(rq); + scx_proxy_resolved(rq); } else { rq_set_donor(rq, next); } diff --git a/kernel/sched/ext/ext.c b/kernel/sched/ext/ext.c index 17dab1543f012..4f2b0f1583989 100644 --- a/kernel/sched/ext/ext.c +++ b/kernel/sched/ext/ext.c @@ -24,6 +24,11 @@ DEFINE_RAW_SPINLOCK(scx_sched_lock); +bool scx_allow_proxy_exec(const struct task_struct *p) +{ + return true; +} + /* * NOTE: sched_ext is in the process of growing multiple scheduler support and * scx_root usage is in a transitional state. Naked dereferences are safe if the @@ -1062,6 +1067,10 @@ static void schedule_deferred_locked(struct rq *rq) schedule_deferred(rq); } +void scx_proxy_resolved(struct rq *rq) +{ +} + void schedule_dsq_reenq(struct scx_sched *sch, struct scx_dispatch_q *dsq, u64 reenq_flags, struct rq *locked_rq) { @@ -3104,6 +3113,10 @@ static void set_next_task_scx(struct rq *rq, struct task_struct *p, bool first) } } +void scx_proxy_donor_start(struct rq *rq) +{ +} + static enum scx_cpu_preempt_reason preempt_reason_from_class(const struct sched_class *class) { diff --git a/kernel/sched/ext/ext.h b/kernel/sched/ext/ext.h index 0b7fc46aee08c..859b9261a8a6b 100644 --- a/kernel/sched/ext/ext.h +++ b/kernel/sched/ext/ext.h @@ -20,6 +20,9 @@ void scx_rq_deactivate(struct rq *rq); int scx_check_setscheduler(struct task_struct *p, int policy); bool task_should_scx(int policy); bool scx_allow_ttwu_queue(const struct task_struct *p); +bool scx_allow_proxy_exec(const struct task_struct *p); +void scx_proxy_donor_start(struct rq *rq); +void scx_proxy_resolved(struct rq *rq); void init_sched_ext_class(void); static inline u32 scx_cpuperf_target(s32 cpu) @@ -54,6 +57,9 @@ static inline void scx_rq_deactivate(struct rq *rq) {} static inline int scx_check_setscheduler(struct task_struct *p, int policy) { return 0; } static inline bool task_on_scx(const struct task_struct *p) { return false; } static inline bool scx_allow_ttwu_queue(const struct task_struct *p) { return true; } +static inline bool scx_allow_proxy_exec(const struct task_struct *p) { return true; } +static inline void scx_proxy_donor_start(struct rq *rq) {} +static inline void scx_proxy_resolved(struct rq *rq) {} static inline void init_sched_ext_class(void) {} #endif /* CONFIG_SCHED_CLASS_EXT */ -- 2.55.0