Merge branch 'timers/core' of... (1f1893d7) · Commits · EulixOS / Software / Kernel

include/linux/interrupt.h

+10 −1

Original line number	Diff line number	Diff line
		@@ -579,7 +579,16 @@ enum
		NR_SOFTIRQS
		};

		#define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ))
		/*
		* The following vectors can be safely ignored after ksoftirqd is parked:
		*
		* _ RCU:
		* 1) rcutree_migrate_callbacks() migrates the queue.
		* 2) rcu_report_dead() reports the final quiescent states.
		*
		* _ IRQ_POLL: irq_poll_cpu_dead() migrates the queue
		*/
		#define SOFTIRQ_HOTPLUG_SAFE_MASK (BIT(RCU_SOFTIRQ) \| BIT(IRQ_POLL_SOFTIRQ))

		/* map softirq index to softirq name. update 'softirq_to_name' in
		* kernel/softirq.c when adding a new softirq.

include/linux/rcutiny.h

+1 −2

Original line number	Diff line number	Diff line
		@@ -64,9 +64,8 @@ static inline void rcu_softirq_qs(void)
		rcu_tasks_qs(current, (preempt)); \
		} while (0)

		static inline int rcu_needs_cpu(u64 basemono, u64 *nextevt)
		static inline int rcu_needs_cpu(void)
		{
		*nextevt = KTIME_MAX;
		return 0;
		}

include/linux/rcutree.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -19,7 +19,7 @@

		void rcu_softirq_qs(void);
		void rcu_note_context_switch(bool preempt);
		int rcu_needs_cpu(u64 basem, u64 *nextevt);
		int rcu_needs_cpu(void);
		void rcu_cpu_stall_reset(void);

		/*

kernel/rcu/tree.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -1086,9 +1086,8 @@ void rcu_irq_enter_irqson(void)
		* Just check whether or not this CPU has non-offloaded RCU callbacks
		* queued.
		*/
		int rcu_needs_cpu(u64 basemono, u64 *nextevt)
		int rcu_needs_cpu(void)
		{
		*nextevt = KTIME_MAX;
		return !rcu_segcblist_empty(&this_cpu_ptr(&rcu_data)->cblist) &&
		!rcu_rdp_is_offloaded(this_cpu_ptr(&rcu_data));
		}

kernel/time/tick-sched.c

+61 −16

Original line number	Diff line number	Diff line
		@@ -169,6 +169,8 @@ static ktime_t tick_init_jiffy_update(void)
		return period;
		}

		#define MAX_STALLED_JIFFIES 5

		static void tick_sched_do_timer(struct tick_sched *ts, ktime_t now)
		{
		int cpu = smp_processor_id();
		@@ -196,6 +198,21 @@ static void tick_sched_do_timer(struct tick_sched *ts, ktime_t now)
		if (tick_do_timer_cpu == cpu)
		tick_do_update_jiffies64(now);

		/*
		* If jiffies update stalled for too long (timekeeper in stop_machine()
		* or VMEXIT'ed for several msecs), force an update.
		*/
		if (ts->last_tick_jiffies != jiffies) {
		ts->stalled_jiffies = 0;
		ts->last_tick_jiffies = READ_ONCE(jiffies);
		} else {
		if (++ts->stalled_jiffies == MAX_STALLED_JIFFIES) {
		tick_do_update_jiffies64(now);
		ts->stalled_jiffies = 0;
		ts->last_tick_jiffies = READ_ONCE(jiffies);
		}
		}

		if (ts->inidle)
		ts->got_idle_tick = 1;
		}
		@@ -768,7 +785,7 @@ static inline bool local_timer_softirq_pending(void)

		static ktime_t tick_nohz_next_event(struct tick_sched *ts, int cpu)
		{
		u64 basemono, next_tick, next_tmr, next_rcu, delta, expires;
		u64 basemono, next_tick, delta, expires;
		unsigned long basejiff;
		unsigned int seq;

		@@ -791,7 +808,7 @@ static ktime_t tick_nohz_next_event(struct tick_sched *ts, int cpu)
		* minimal delta which brings us back to this place
		* immediately. Lather, rinse and repeat...
		*/
		if (rcu_needs_cpu(basemono, &next_rcu) \|\| arch_needs_cpu() \|\|
		if (rcu_needs_cpu() \|\| arch_needs_cpu() \|\|
		irq_work_needs_cpu() \|\| local_timer_softirq_pending()) {
		next_tick = basemono + TICK_NSEC;
		} else {
		@@ -802,10 +819,8 @@ static ktime_t tick_nohz_next_event(struct tick_sched *ts, int cpu)
		* disabled this also looks at the next expiring
		* hrtimer.
		*/
		next_tmr = get_next_timer_interrupt(basejiff, basemono);
		ts->next_timer = next_tmr;
		/* Take the next rcu event into account */
		next_tick = next_rcu < next_tmr ? next_rcu : next_tmr;
		next_tick = get_next_timer_interrupt(basejiff, basemono);
		ts->next_timer = next_tick;
		}

		/*
		@@ -984,6 +999,45 @@ static void tick_nohz_full_update_tick(struct tick_sched *ts)
		__tick_nohz_full_update_tick(ts, ktime_get());
		}

		/*
		* A pending softirq outside an IRQ (or softirq disabled section) context
		* should be waiting for ksoftirqd to handle it. Therefore we shouldn't
		* reach here due to the need_resched() early check in can_stop_idle_tick().
		*
		* However if we are between CPUHP_AP_SMPBOOT_THREADS and CPU_TEARDOWN_CPU on the
		* cpu_down() process, softirqs can still be raised while ksoftirqd is parked,
		* triggering the below since wakep_softirqd() is ignored.
		*
		*/
		static bool report_idle_softirq(void)
		{
		static int ratelimit;
		unsigned int pending = local_softirq_pending();

		if (likely(!pending))
		return false;

		/* Some softirqs claim to be safe against hotplug and ksoftirqd parking */
		if (!cpu_active(smp_processor_id())) {
		pending &= ~SOFTIRQ_HOTPLUG_SAFE_MASK;
		if (!pending)
		return false;
		}

		if (ratelimit < 10)
		return false;

		/* On RT, softirqs handling may be waiting on some lock */
		if (!local_bh_blocked())
		return false;

		pr_warn("NOHZ tick-stop error: local softirq work is pending, handler #%02x!!!\n",
		pending);
		ratelimit++;

		return true;
		}

		static bool can_stop_idle_tick(int cpu, struct tick_sched *ts)
		{
		/*
		@@ -1010,17 +1064,8 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts)
		if (need_resched())
		return false;

		if (unlikely(local_softirq_pending())) {
		static int ratelimit;

		if (ratelimit < 10 && !local_bh_blocked() &&
		(local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) {
		pr_warn("NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #%02x!!!\n",
		(unsigned int) local_softirq_pending());
		ratelimit++;
		}
		if (unlikely(report_idle_softirq()))
		return false;
		}

		if (tick_nohz_full_enabled()) {
		/*