Merge "sched: Add trace point to track preemption disable callers" (38696730) · Commits · e / devices / android_kernel_fairphone_FP3

include/linux/sched/sysctl.h

+4 −0

Original line number	Original line	Diff line number	Diff line
	@@ -42,6 +42,10 @@ walt_proc_update_handler(struct ctl_table *table, int write,

	#endif /* CONFIG_SCHED_WALT */		#endif /* CONFIG_SCHED_WALT */

			#if defined(CONFIG_PREEMPT_TRACER) \|\| defined(CONFIG_IRQSOFF_TRACER)
			extern unsigned int sysctl_preemptoff_tracing_threshold_ns;
			#endif

	enum sched_tunable_scaling {		enum sched_tunable_scaling {
	SCHED_TUNABLESCALING_NONE,		SCHED_TUNABLESCALING_NONE,
	SCHED_TUNABLESCALING_LOG,		SCHED_TUNABLESCALING_LOG,

include/trace/events/sched.h

+33 −0

Original line number	Original line	Diff line number	Diff line
	@@ -1875,6 +1875,39 @@ TRACE_EVENT(sched_isolate,
	__entry->requested_cpu, __entry->isolated_cpus,		__entry->requested_cpu, __entry->isolated_cpus,
	__entry->time, __entry->isolate)		__entry->time, __entry->isolate)
	);		);

			TRACE_EVENT(sched_preempt_disable,

			TP_PROTO(u64 delta, bool irqs_disabled,
			unsigned long caddr0, unsigned long caddr1,
			unsigned long caddr2, unsigned long caddr3),

			TP_ARGS(delta, irqs_disabled, caddr0, caddr1, caddr2, caddr3),

			TP_STRUCT__entry(
			__field(u64, delta)
			__field(bool, irqs_disabled)
			__field(void*, caddr0)
			__field(void*, caddr1)
			__field(void*, caddr2)
			__field(void*, caddr3)
			),

			TP_fast_assign(
			__entry->delta = delta;
			__entry->irqs_disabled = irqs_disabled;
			__entry->caddr0 = (void *)caddr0;
			__entry->caddr1 = (void *)caddr1;
			__entry->caddr2 = (void *)caddr2;
			__entry->caddr3 = (void *)caddr3;
			),

			TP_printk("delta=%llu(ns) irqs_d=%d Callers:(%pf<-%pf<-%pf<-%pf)",
			__entry->delta, __entry->irqs_disabled,
			__entry->caddr0, __entry->caddr1,
			__entry->caddr2, __entry->caddr3)
			);

	#endif /* _TRACE_SCHED_H */		#endif /* _TRACE_SCHED_H */

	/* This part must be outside protection */		/* This part must be outside protection */

kernel/sched/core.c

+36 −1

Original line number	Original line	Diff line number	Diff line
	@@ -3322,17 +3322,39 @@ u64 scheduler_tick_max_deferment(void)

	#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) \|\| \		#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) \|\| \
	defined(CONFIG_PREEMPT_TRACER))		defined(CONFIG_PREEMPT_TRACER))
			/*
			* preemptoff stack tracing threshold in ns.
			* default: 1ms
			*/
			unsigned int sysctl_preemptoff_tracing_threshold_ns = 1000000UL;

			struct preempt_store {
			u64 ts;
			unsigned long caddr[4];
			bool irqs_disabled;
			};

			static DEFINE_PER_CPU(struct preempt_store, the_ps);
	/*		/*
	* If the value passed in is equal to the current preempt count		* If the value passed in is equal to the current preempt count
	* then we just disabled preemption. Start timing the latency.		* then we just disabled preemption. Start timing the latency.
	*/		*/
	static inline void preempt_latency_start(int val)		static inline void preempt_latency_start(int val)
	{		{
			struct preempt_store *ps = &per_cpu(the_ps, raw_smp_processor_id());

	if (preempt_count() == val) {		if (preempt_count() == val) {
	unsigned long ip = get_lock_parent_ip();		unsigned long ip = get_lock_parent_ip();
	#ifdef CONFIG_DEBUG_PREEMPT		#ifdef CONFIG_DEBUG_PREEMPT
	current->preempt_disable_ip = ip;		current->preempt_disable_ip = ip;
	#endif		#endif
			ps->ts = sched_clock();
			ps->caddr[0] = CALLER_ADDR0;
			ps->caddr[1] = CALLER_ADDR1;
			ps->caddr[2] = CALLER_ADDR2;
			ps->caddr[3] = CALLER_ADDR3;
			ps->irqs_disabled = irqs_disabled();

	trace_preempt_off(CALLER_ADDR0, ip);		trace_preempt_off(CALLER_ADDR0, ip);
	}		}
	}		}
	@@ -3365,9 +3387,22 @@ NOKPROBE_SYMBOL(preempt_count_add);
	*/		*/
	static inline void preempt_latency_stop(int val)		static inline void preempt_latency_stop(int val)
	{		{
	if (preempt_count() == val)		if (preempt_count() == val) {
			struct preempt_store *ps = &per_cpu(the_ps,
			raw_smp_processor_id());
			u64 delta = sched_clock() - ps->ts;

			/*
			* Trace preempt disable stack if preemption
			* is disabled for more than the threshold.
			*/
			if (delta > sysctl_preemptoff_tracing_threshold_ns)
			trace_sched_preempt_disable(delta, ps->irqs_disabled,
			ps->caddr[0], ps->caddr[1],
			ps->caddr[2], ps->caddr[3]);
	trace_preempt_on(CALLER_ADDR0, get_lock_parent_ip());		trace_preempt_on(CALLER_ADDR0, get_lock_parent_ip());
	}		}
			}

	void preempt_count_sub(int val)		void preempt_count_sub(int val)
	{		{

kernel/sysctl.c

+9 −0

Original line number	Original line	Diff line number	Diff line
	@@ -291,6 +291,15 @@ static struct ctl_table kern_table[] = {
	.mode = 0644,		.mode = 0644,
	.proc_handler = proc_dointvec,		.proc_handler = proc_dointvec,
	},		},
			#if defined(CONFIG_PREEMPT_TRACER) \|\| defined(CONFIG_IRQSOFF_TRACER)
			{
			.procname = "preemptoff_tracing_threshold_ns",
			.data = &sysctl_preemptoff_tracing_threshold_ns,
			.maxlen = sizeof(unsigned int),
			.mode = 0644,
			.proc_handler = proc_dointvec,
			},
			#endif
	#ifdef CONFIG_SCHED_WALT		#ifdef CONFIG_SCHED_WALT
	{		{
	.procname = "sched_cpu_high_irqload",		.procname = "sched_cpu_high_irqload",