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-rw-r--r--kernel/sched/core.c110
1 files changed, 68 insertions, 42 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 44999505e1bf..24beb9bb4c3e 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;
@@ -2951,6 +2922,47 @@ 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 +6339,10 @@ 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 +7419,12 @@ 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 +7853,11 @@ 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 +8230,7 @@ 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,