From: Zhang Qiao zhangqiao22@huawei.com
hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8MF4R CVE: NA
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If online tasks occupy 100% CPU resources, offline tasks can't be scheduled since offline tasks are throttled, as a result, offline task can't timely respond after receiving SIGKILL signal.
Signed-off-by: Zhang Qiao zhangqiao22@huawei.com Signed-off-by: Wenyu Huang huangwenyu5@huawei.com --- include/linux/cgroup.h | 4 ++++ include/linux/sched.h | 4 ++++ kernel/cgroup/cgroup.c | 22 ++++++++++++++++++++++ kernel/sched/core.c | 32 ++++++++++++++++++++++++++++++++ kernel/signal.c | 3 +++ 5 files changed, 65 insertions(+)
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index b307013b9c6c..7fa51b600ee8 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -855,4 +855,8 @@ static inline void cgroup_bpf_put(struct cgroup *cgrp) {}
#endif /* CONFIG_CGROUP_BPF */
+#ifdef CONFIG_QOS_SCHED +void cgroup_move_task_to_root(struct task_struct *tsk); +#endif + #endif /* _LINUX_CGROUP_H */ diff --git a/include/linux/sched.h b/include/linux/sched.h index 77f01ac385f7..d796894806f4 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2457,4 +2457,8 @@ static inline int sched_core_idle_cpu(int cpu) { return idle_cpu(cpu); }
extern void sched_set_stop_task(int cpu, struct task_struct *stop);
+#ifdef CONFIG_QOS_SCHED +void sched_move_offline_task(struct task_struct *p); +#endif + #endif diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 518725b57200..487330fedd93 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -2936,6 +2936,28 @@ void cgroup_procs_write_finish(struct task_struct *task, bool threadgroup_locked ss->post_attach(); }
+#ifdef CONFIG_QOS_SCHED +void cgroup_move_task_to_root(struct task_struct *tsk) +{ + struct css_set *css; + struct cgroup *cpu_cgrp; + struct cgroup *cpu_root_cgrp; + + mutex_lock(&cgroup_mutex); + percpu_down_write(&cgroup_threadgroup_rwsem); + + spin_lock_irq(&css_set_lock); + css = task_css_set(tsk); + cpu_cgrp = css->subsys[cpu_cgrp_id]->cgroup; + cpu_root_cgrp = &cpu_cgrp->root->cgrp; + spin_unlock_irq(&css_set_lock); + + (void)cgroup_attach_task(cpu_root_cgrp, tsk, false); + percpu_up_write(&cgroup_threadgroup_rwsem); + mutex_unlock(&cgroup_mutex); +} +#endif + static void cgroup_print_ss_mask(struct seq_file *seq, u16 ss_mask) { struct cgroup_subsys *ss; diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 0888b580a010..ac3de8f7e27d 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -10384,6 +10384,38 @@ static void sched_change_qos_group(struct task_struct *tsk, struct task_group *t __setscheduler_prio(tsk, normal_prio(tsk)); } } + +struct offline_args { + struct work_struct work; + struct task_struct *p; +}; + +static void sched_move_work(struct work_struct *work) +{ + struct sched_param param = { .sched_priority = 0 }; + struct offline_args *args = container_of(work, struct offline_args, work); + + cgroup_move_task_to_root(args->p); + sched_setscheduler(args->p, SCHED_NORMAL, ¶m); + put_task_struct(args->p); + kfree(args); +} + +void sched_move_offline_task(struct task_struct *p) +{ + struct offline_args *args; + + if (unlikely(task_group(p)->qos_level != -1)) + return; + + args = kmalloc(sizeof(struct offline_args), GFP_ATOMIC); + if (args) { + get_task_struct(p); + args->p = p; + INIT_WORK(&args->work, sched_move_work); + queue_work(system_highpri_wq, &args->work); + } +} #endif
static inline void alloc_uclamp_sched_group(struct task_group *tg, diff --git a/kernel/signal.c b/kernel/signal.c index 09019017d669..28cddef39778 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1060,6 +1060,9 @@ static void complete_signal(int sig, struct task_struct *p, enum pid_type type) signal->group_stop_count = 0; t = p; do { +#ifdef CONFIG_QOS_SCHED + sched_move_offline_task(t); +#endif task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK); sigaddset(&t->pending.signal, SIGKILL); signal_wake_up(t, 1);