1 // SPDX-License-Identifier: GPL-2.0
3  * trace task wakeup timings
5  * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
10  *  Copyright (C) 2004-2006 Ingo Molnar
28 static unsigned			wakeup_prio = -1;
44 # define is_graph(tr) ((tr)->trace_flags & TRACE_ITER_DISPLAY_GRAPH)
54  * Prologue for the wakeup function tracers.
57  *            is disabled and data->disabled is incremented.
59  *            is not disabled and data->disabled is
85 	*data = per_cpu_ptr(tr->array_buffer.data, cpu);  in func_prolog_preempt_disable()
86 	disabled = atomic_inc_return(&(*data)->disabled);  in func_prolog_preempt_disable()
93 	atomic_dec(&(*data)->disabled);  in func_prolog_preempt_disable()
110 	tr->max_latency = 0;  in wakeup_display_graph()
131 	if (ftrace_graph_notrace_addr(trace->func))  in wakeup_graph_entry()
139 	atomic_dec(&data->disabled);  in wakeup_graph_entry()
159 	atomic_dec(&data->disabled);  in wakeup_graph_return()
172 	if (is_graph(iter->tr))  in wakeup_trace_open()
178 	if (iter->private)  in wakeup_trace_close()
195 	if (is_graph(iter->tr))  in wakeup_print_line()
211  * wakeup uses its own tracer function to keep the overhead down:
229 	atomic_dec(&data->disabled);  in wakeup_tracer_call()
238 	if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION)))  in register_wakeup_function()
244 		ret = register_ftrace_function(tr->ops);  in register_wakeup_function()
260 		unregister_ftrace_function(tr->ops);  in unregister_wakeup_function()
316 	struct tracer *tracer = tr->current_trace;  in wakeup_flag_changed()
351  * Should this new latency be reported/recorded?
359 		if (delta <= tr->max_latency)  in report_latency()
381 	struct trace_buffer *buffer = tr->array_buffer.buffer;  in tracing_sched_switch_trace()
390 	entry->prev_pid			= prev->pid;  in tracing_sched_switch_trace()
391 	entry->prev_prio		= prev->prio;  in tracing_sched_switch_trace()
392 	entry->prev_state		= task_state_index(prev);  in tracing_sched_switch_trace()
393 	entry->next_pid			= next->pid;  in tracing_sched_switch_trace()
394 	entry->next_prio		= next->prio;  in tracing_sched_switch_trace()
395 	entry->next_state		= task_state_index(next);  in tracing_sched_switch_trace()
396 	entry->next_cpu	= task_cpu(next);  in tracing_sched_switch_trace()
411 	struct trace_buffer *buffer = tr->array_buffer.buffer;  in tracing_sched_wakeup_trace()
418 	entry->prev_pid			= curr->pid;  in tracing_sched_wakeup_trace()
419 	entry->prev_prio		= curr->prio;  in tracing_sched_wakeup_trace()
420 	entry->prev_state		= task_state_index(curr);  in tracing_sched_wakeup_trace()
421 	entry->next_pid			= wakee->pid;  in tracing_sched_wakeup_trace()
422 	entry->next_prio		= wakee->prio;  in tracing_sched_wakeup_trace()
423 	entry->next_state		= task_state_index(wakee);  in tracing_sched_wakeup_trace()
424 	entry->next_cpu			= task_cpu(wakee);  in tracing_sched_wakeup_trace()
462 	disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled);  in probe_wakeup_sched_switch()
474 	data = per_cpu_ptr(wakeup_trace->array_buffer.data, wakeup_cpu);  in probe_wakeup_sched_switch()
480 	T0 = data->preempt_timestamp;  in probe_wakeup_sched_switch()
482 	delta = T1-T0;  in probe_wakeup_sched_switch()
488 		wakeup_trace->max_latency = delta;  in probe_wakeup_sched_switch()
497 	atomic_dec(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled);  in probe_wakeup_sched_switch()
502 	wakeup_cpu = -1;  in __wakeup_reset()
503 	wakeup_prio = -1;  in __wakeup_reset()
516 	tracing_reset_online_cpus(&tr->array_buffer);  in wakeup_reset()
542 	 *  - wakeup tracer handles all tasks in the system, independently  in probe_wakeup()
544 	 *  - wakeup_rt tracer handles tasks belonging to sched_dl and  in probe_wakeup()
546 	 *  - wakeup_dl handles tasks belonging to sched_dl class only.  in probe_wakeup()
550 	    (!dl_task(p) && (p->prio >= wakeup_prio || p->prio >= current->prio)))  in probe_wakeup()
554 	disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled);  in probe_wakeup()
563 	    (!dl_task(p) && p->prio >= wakeup_prio))  in probe_wakeup()
571 	wakeup_prio = p->prio;  in probe_wakeup()
574 	 * Once you start tracing a -deadline task, don't bother tracing  in probe_wakeup()
586 	data = per_cpu_ptr(wakeup_trace->array_buffer.data, wakeup_cpu);  in probe_wakeup()
587 	data->preempt_timestamp = ftrace_now(cpu);  in probe_wakeup()
601 	atomic_dec(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled);  in probe_wakeup()
610 		pr_info("wakeup trace: Couldn't activate tracepoint"  in start_wakeup_tracer()
617 		pr_info("wakeup trace: Couldn't activate tracepoint"  in start_wakeup_tracer()
631 		pr_info("wakeup trace: Couldn't activate tracepoint"  in start_wakeup_tracer()
648 		printk(KERN_ERR "failed to start wakeup tracer\n");  in start_wakeup_tracer()
673 	save_flags = tr->trace_flags;  in __wakeup_tracer_init()
675 	/* non overwrite screws up the latency tracers */  in __wakeup_tracer_init()
679 	tr->max_latency = 0;  in __wakeup_tracer_init()
691 		return -EBUSY;  in wakeup_tracer_init()
701 		return -EBUSY;  in wakeup_rt_tracer_init()
711 		return -EBUSY;  in wakeup_dl_tracer_init()
746 	.name		= "wakeup",