diff options
Diffstat (limited to 'kernel/sched/core.c')
| -rw-r--r-- | kernel/sched/core.c | 118 |
1 files changed, 74 insertions, 44 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 44999505e1bf..89e7283015a6 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2475,44 +2475,6 @@ EXPORT_PER_CPU_SYMBOL(kstat); EXPORT_PER_CPU_SYMBOL(kernel_cpustat); /* - * Return any ns on the sched_clock that have not yet been accounted in - * @p in case that task is currently running. - * - * Called with task_rq_lock() held on @rq. - */ -static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) -{ - u64 ns = 0; - - /* - * Must be ->curr _and_ ->on_rq. If dequeued, we would - * project cycles that may never be accounted to this - * thread, breaking clock_gettime(). - */ - if (task_current(rq, p) && task_on_rq_queued(p)) { - update_rq_clock(rq); - ns = rq_clock_task(rq) - p->se.exec_start; - if ((s64)ns < 0) - ns = 0; - } - - return ns; -} - -unsigned long long task_delta_exec(struct task_struct *p) -{ - unsigned long flags; - struct rq *rq; - u64 ns = 0; - - rq = task_rq_lock(p, &flags); - ns = do_task_delta_exec(p, rq); - task_rq_unlock(rq, p, &flags); - - return ns; -} - -/* * Return accounted runtime for the task. * In case the task is currently running, return the runtime plus current's * pending runtime that have not been accounted yet. @@ -2521,7 +2483,7 @@ unsigned long long task_sched_runtime(struct task_struct *p) { unsigned long flags; struct rq *rq; - u64 ns = 0; + u64 ns; #if defined(CONFIG_64BIT) && defined(CONFIG_SMP) /* @@ -2540,7 +2502,16 @@ unsigned long long task_sched_runtime(struct task_struct *p) #endif rq = task_rq_lock(p, &flags); - ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); + /* + * Must be ->curr _and_ ->on_rq. If dequeued, we would + * project cycles that may never be accounted to this + * thread, breaking clock_gettime(). + */ + if (task_current(rq, p) && task_on_rq_queued(p)) { + update_rq_clock(rq); + p->sched_class->update_curr(rq); + } + ns = p->se.sum_exec_runtime; task_rq_unlock(rq, p, &flags); return ns; @@ -2903,10 +2874,14 @@ asmlinkage __visible void __sched schedule_user(void) * or we have been woken up remotely but the IPI has not yet arrived, * we haven't yet exited the RCU idle mode. Do it here manually until * we find a better solution. + * + * NB: There are buggy callers of this function. Ideally we + * should warn if prev_state != IN_USER, but that will trigger + * too frequently to make sense yet. */ - user_exit(); + enum ctx_state prev_state = exception_enter(); schedule(); - user_enter(); + exception_exit(prev_state); } #endif @@ -2951,6 +2926,47 @@ asmlinkage __visible void __sched notrace preempt_schedule(void) } NOKPROBE_SYMBOL(preempt_schedule); EXPORT_SYMBOL(preempt_schedule); + +#ifdef CONFIG_CONTEXT_TRACKING +/** + * preempt_schedule_context - preempt_schedule called by tracing + * + * The tracing infrastructure uses preempt_enable_notrace to prevent + * recursion and tracing preempt enabling caused by the tracing + * infrastructure itself. But as tracing can happen in areas coming + * from userspace or just about to enter userspace, a preempt enable + * can occur before user_exit() is called. This will cause the scheduler + * to be called when the system is still in usermode. + * + * To prevent this, the preempt_enable_notrace will use this function + * instead of preempt_schedule() to exit user context if needed before + * calling the scheduler. + */ +asmlinkage __visible void __sched notrace preempt_schedule_context(void) +{ + enum ctx_state prev_ctx; + + if (likely(!preemptible())) + return; + + do { + __preempt_count_add(PREEMPT_ACTIVE); + /* + * Needs preempt disabled in case user_exit() is traced + * and the tracer calls preempt_enable_notrace() causing + * an infinite recursion. + */ + prev_ctx = exception_enter(); + __schedule(); + exception_exit(prev_ctx); + + __preempt_count_sub(PREEMPT_ACTIVE); + barrier(); + } while (need_resched()); +} +EXPORT_SYMBOL_GPL(preempt_schedule_context); +#endif /* CONFIG_CONTEXT_TRACKING */ + #endif /* CONFIG_PREEMPT */ /* @@ -6327,6 +6343,10 @@ static void sched_init_numa(void) if (!sched_debug()) break; } + + if (!level) + return; + /* * 'level' contains the number of unique distances, excluding the * identity distance node_distance(i,i). @@ -7403,8 +7423,12 @@ void sched_move_task(struct task_struct *tsk) if (unlikely(running)) put_prev_task(rq, tsk); - tg = container_of(task_css_check(tsk, cpu_cgrp_id, - lockdep_is_held(&tsk->sighand->siglock)), + /* + * All callers are synchronized by task_rq_lock(); we do not use RCU + * which is pointless here. Thus, we pass "true" to task_css_check() + * to prevent lockdep warnings. + */ + tg = container_of(task_css_check(tsk, cpu_cgrp_id, true), struct task_group, css); tg = autogroup_task_group(tsk, tg); tsk->sched_task_group = tg; @@ -7833,6 +7857,11 @@ static void cpu_cgroup_css_offline(struct cgroup_subsys_state *css) sched_offline_group(tg); } +static void cpu_cgroup_fork(struct task_struct *task) +{ + sched_move_task(task); +} + static int cpu_cgroup_can_attach(struct cgroup_subsys_state *css, struct cgroup_taskset *tset) { @@ -8205,6 +8234,7 @@ struct cgroup_subsys cpu_cgrp_subsys = { .css_free = cpu_cgroup_css_free, .css_online = cpu_cgroup_css_online, .css_offline = cpu_cgroup_css_offline, + .fork = cpu_cgroup_fork, .can_attach = cpu_cgroup_can_attach, .attach = cpu_cgroup_attach, .exit = cpu_cgroup_exit, |