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-rw-r--r--kernel/sched/core.c6
-rw-r--r--kernel/sched/cputime.c12
-rw-r--r--kernel/softirq.c3
-rw-r--r--kernel/time/tick-sched.c7
4 files changed, 21 insertions, 7 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 76f9deeaa942..77563109c0ea 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1918,7 +1918,7 @@ static void __init init_uclamp_rq(struct rq *rq)
};
}
- rq->uclamp_flags = 0;
+ rq->uclamp_flags = UCLAMP_FLAG_IDLE;
}
static void __init init_uclamp(void)
@@ -6617,11 +6617,11 @@ static int __init setup_preempt_mode(char *str)
int mode = sched_dynamic_mode(str);
if (mode < 0) {
pr_warn("Dynamic Preempt: unsupported mode: %s\n", str);
- return 1;
+ return 0;
}
sched_dynamic_update(mode);
- return 0;
+ return 1;
}
__setup("preempt=", setup_preempt_mode);
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 872e481d5098..9392aea1804e 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -615,7 +615,8 @@ void task_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st)
.sum_exec_runtime = p->se.sum_exec_runtime,
};
- task_cputime(p, &cputime.utime, &cputime.stime);
+ if (task_cputime(p, &cputime.utime, &cputime.stime))
+ cputime.sum_exec_runtime = task_sched_runtime(p);
cputime_adjust(&cputime, &p->prev_cputime, ut, st);
}
EXPORT_SYMBOL_GPL(task_cputime_adjusted);
@@ -828,19 +829,21 @@ u64 task_gtime(struct task_struct *t)
* add up the pending nohz execution time since the last
* cputime snapshot.
*/
-void task_cputime(struct task_struct *t, u64 *utime, u64 *stime)
+bool task_cputime(struct task_struct *t, u64 *utime, u64 *stime)
{
struct vtime *vtime = &t->vtime;
unsigned int seq;
u64 delta;
+ int ret;
if (!vtime_accounting_enabled()) {
*utime = t->utime;
*stime = t->stime;
- return;
+ return false;
}
do {
+ ret = false;
seq = read_seqcount_begin(&vtime->seqcount);
*utime = t->utime;
@@ -850,6 +853,7 @@ void task_cputime(struct task_struct *t, u64 *utime, u64 *stime)
if (vtime->state < VTIME_SYS)
continue;
+ ret = true;
delta = vtime_delta(vtime);
/*
@@ -861,6 +865,8 @@ void task_cputime(struct task_struct *t, u64 *utime, u64 *stime)
else
*utime += vtime->utime + delta;
} while (read_seqcount_retry(&vtime->seqcount, seq));
+
+ return ret;
}
static int vtime_state_fetch(struct vtime *vtime, int cpu)
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 322b65d45676..41f470929e99 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -595,7 +595,8 @@ void irq_enter_rcu(void)
{
__irq_enter_raw();
- if (is_idle_task(current) && (irq_count() == HARDIRQ_OFFSET))
+ if (tick_nohz_full_cpu(smp_processor_id()) ||
+ (is_idle_task(current) && (irq_count() == HARDIRQ_OFFSET)))
tick_irq_enter();
account_hardirq_enter(current);
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 6bffe5af8cb1..17a283ce2b20 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -1375,6 +1375,13 @@ static inline void tick_nohz_irq_enter(void)
now = ktime_get();
if (ts->idle_active)
tick_nohz_stop_idle(ts, now);
+ /*
+ * If all CPUs are idle. We may need to update a stale jiffies value.
+ * Note nohz_full is a special case: a timekeeper is guaranteed to stay
+ * alive but it might be busy looping with interrupts disabled in some
+ * rare case (typically stop machine). So we must make sure we have a
+ * last resort.
+ */
if (ts->tick_stopped)
tick_nohz_update_jiffies(now);
}