Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Steven Rostedt | 2415 | 76.96% | 41 | 63.08% |
Jiri Olsa | 318 | 10.13% | 2 | 3.08% |
Dario Faggioli | 199 | 6.34% | 2 | 3.08% |
Mathieu Desnoyers | 136 | 4.33% | 2 | 3.08% |
Peter Zijlstra | 15 | 0.48% | 3 | 4.62% |
Thomas Gleixner | 11 | 0.35% | 4 | 6.15% |
Carsten Emde | 11 | 0.35% | 1 | 1.54% |
Motohiro Kosaki | 8 | 0.25% | 1 | 1.54% |
Zhou Chengming | 5 | 0.16% | 1 | 1.54% |
Hiraku Toyooka | 4 | 0.13% | 1 | 1.54% |
Yaowei Bai | 4 | 0.13% | 1 | 1.54% |
Frédéric Weisbecker | 4 | 0.13% | 1 | 1.54% |
Clark Williams | 3 | 0.10% | 1 | 1.54% |
Ingo Molnar | 2 | 0.06% | 1 | 1.54% |
Wenji Huang | 1 | 0.03% | 1 | 1.54% |
Greg Kroah-Hartman | 1 | 0.03% | 1 | 1.54% |
Nadia Yvette Chambers | 1 | 0.03% | 1 | 1.54% |
Total | 3138 | 65 |
// SPDX-License-Identifier: GPL-2.0 /* * trace task wakeup timings * * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> * * Based on code from the latency_tracer, that is: * * Copyright (C) 2004-2006 Ingo Molnar * Copyright (C) 2004 Nadia Yvette Chambers */ #include <linux/module.h> #include <linux/kallsyms.h> #include <linux/uaccess.h> #include <linux/ftrace.h> #include <linux/sched/rt.h> #include <linux/sched/deadline.h> #include <trace/events/sched.h> #include "trace.h" static struct trace_array *wakeup_trace; static int __read_mostly tracer_enabled; static struct task_struct *wakeup_task; static int wakeup_cpu; static int wakeup_current_cpu; static unsigned wakeup_prio = -1; static int wakeup_rt; static int wakeup_dl; static int tracing_dl = 0; static arch_spinlock_t wakeup_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; static void wakeup_reset(struct trace_array *tr); static void __wakeup_reset(struct trace_array *tr); static int start_func_tracer(struct trace_array *tr, int graph); static void stop_func_tracer(struct trace_array *tr, int graph); static int save_flags; #ifdef CONFIG_FUNCTION_GRAPH_TRACER # define is_graph(tr) ((tr)->trace_flags & TRACE_ITER_DISPLAY_GRAPH) #else # define is_graph(tr) false #endif #ifdef CONFIG_FUNCTION_TRACER static bool function_enabled; /* * Prologue for the wakeup function tracers. * * Returns 1 if it is OK to continue, and preemption * is disabled and data->disabled is incremented. * 0 if the trace is to be ignored, and preemption * is not disabled and data->disabled is * kept the same. * * Note, this function is also used outside this ifdef but * inside the #ifdef of the function graph tracer below. * This is OK, since the function graph tracer is * dependent on the function tracer. */ static int func_prolog_preempt_disable(struct trace_array *tr, struct trace_array_cpu **data, int *pc) { long disabled; int cpu; if (likely(!wakeup_task)) return 0; *pc = preempt_count(); preempt_disable_notrace(); cpu = raw_smp_processor_id(); if (cpu != wakeup_current_cpu) goto out_enable; *data = per_cpu_ptr(tr->trace_buffer.data, cpu); disabled = atomic_inc_return(&(*data)->disabled); if (unlikely(disabled != 1)) goto out; return 1; out: atomic_dec(&(*data)->disabled); out_enable: preempt_enable_notrace(); return 0; } #ifdef CONFIG_FUNCTION_GRAPH_TRACER static int wakeup_display_graph(struct trace_array *tr, int set) { if (!(is_graph(tr) ^ set)) return 0; stop_func_tracer(tr, !set); wakeup_reset(wakeup_trace); tr->max_latency = 0; return start_func_tracer(tr, set); } static int wakeup_graph_entry(struct ftrace_graph_ent *trace) { struct trace_array *tr = wakeup_trace; struct trace_array_cpu *data; unsigned long flags; int pc, ret = 0; if (ftrace_graph_ignore_func(trace)) return 0; /* * Do not trace a function if it's filtered by set_graph_notrace. * Make the index of ret stack negative to indicate that it should * ignore further functions. But it needs its own ret stack entry * to recover the original index in order to continue tracing after * returning from the function. */ if (ftrace_graph_notrace_addr(trace->func)) return 1; if (!func_prolog_preempt_disable(tr, &data, &pc)) return 0; local_save_flags(flags); ret = __trace_graph_entry(tr, trace, flags, pc); atomic_dec(&data->disabled); preempt_enable_notrace(); return ret; } static void wakeup_graph_return(struct ftrace_graph_ret *trace) { struct trace_array *tr = wakeup_trace; struct trace_array_cpu *data; unsigned long flags; int pc; ftrace_graph_addr_finish(trace); if (!func_prolog_preempt_disable(tr, &data, &pc)) return; local_save_flags(flags); __trace_graph_return(tr, trace, flags, pc); atomic_dec(&data->disabled); preempt_enable_notrace(); return; } static struct fgraph_ops fgraph_wakeup_ops = { .entryfunc = &wakeup_graph_entry, .retfunc = &wakeup_graph_return, }; static void wakeup_trace_open(struct trace_iterator *iter) { if (is_graph(iter->tr)) graph_trace_open(iter); } static void wakeup_trace_close(struct trace_iterator *iter) { if (iter->private) graph_trace_close(iter); } #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_PROC | \ TRACE_GRAPH_PRINT_ABS_TIME | \ TRACE_GRAPH_PRINT_DURATION) static enum print_line_t wakeup_print_line(struct trace_iterator *iter) { /* * In graph mode call the graph tracer output function, * otherwise go with the TRACE_FN event handler */ if (is_graph(iter->tr)) return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS); return TRACE_TYPE_UNHANDLED; } static void wakeup_print_header(struct seq_file *s) { if (is_graph(wakeup_trace)) print_graph_headers_flags(s, GRAPH_TRACER_FLAGS); else trace_default_header(s); } #endif /* else CONFIG_FUNCTION_GRAPH_TRACER */ /* * wakeup uses its own tracer function to keep the overhead down: */ static void wakeup_tracer_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct pt_regs *pt_regs) { struct trace_array *tr = wakeup_trace; struct trace_array_cpu *data; unsigned long flags; int pc; if (!func_prolog_preempt_disable(tr, &data, &pc)) return; local_irq_save(flags); trace_function(tr, ip, parent_ip, flags, pc); local_irq_restore(flags); atomic_dec(&data->disabled); preempt_enable_notrace(); } static int register_wakeup_function(struct trace_array *tr, int graph, int set) { int ret; /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */ if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION))) return 0; if (graph) ret = register_ftrace_graph(&fgraph_wakeup_ops); else ret = register_ftrace_function(tr->ops); if (!ret) function_enabled = true; return ret; } static void unregister_wakeup_function(struct trace_array *tr, int graph) { if (!function_enabled) return; if (graph) unregister_ftrace_graph(&fgraph_wakeup_ops); else unregister_ftrace_function(tr->ops); function_enabled = false; } static int wakeup_function_set(struct trace_array *tr, u32 mask, int set) { if (!(mask & TRACE_ITER_FUNCTION)) return 0; if (set) register_wakeup_function(tr, is_graph(tr), 1); else unregister_wakeup_function(tr, is_graph(tr)); return 1; } #else /* CONFIG_FUNCTION_TRACER */ static int register_wakeup_function(struct trace_array *tr, int graph, int set) { return 0; } static void unregister_wakeup_function(struct trace_array *tr, int graph) { } static int wakeup_function_set(struct trace_array *tr, u32 mask, int set) { return 0; } #endif /* else CONFIG_FUNCTION_TRACER */ #ifndef CONFIG_FUNCTION_GRAPH_TRACER static enum print_line_t wakeup_print_line(struct trace_iterator *iter) { return TRACE_TYPE_UNHANDLED; } static void wakeup_trace_open(struct trace_iterator *iter) { } static void wakeup_trace_close(struct trace_iterator *iter) { } static void wakeup_print_header(struct seq_file *s) { trace_default_header(s); } #endif /* !CONFIG_FUNCTION_GRAPH_TRACER */ static void __trace_function(struct trace_array *tr, unsigned long ip, unsigned long parent_ip, unsigned long flags, int pc) { if (is_graph(tr)) trace_graph_function(tr, ip, parent_ip, flags, pc); else trace_function(tr, ip, parent_ip, flags, pc); } static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set) { struct tracer *tracer = tr->current_trace; if (wakeup_function_set(tr, mask, set)) return 0; #ifdef CONFIG_FUNCTION_GRAPH_TRACER if (mask & TRACE_ITER_DISPLAY_GRAPH) return wakeup_display_graph(tr, set); #endif return trace_keep_overwrite(tracer, mask, set); } static int start_func_tracer(struct trace_array *tr, int graph) { int ret; ret = register_wakeup_function(tr, graph, 0); if (!ret && tracing_is_enabled()) tracer_enabled = 1; else tracer_enabled = 0; return ret; } static void stop_func_tracer(struct trace_array *tr, int graph) { tracer_enabled = 0; unregister_wakeup_function(tr, graph); } /* * Should this new latency be reported/recorded? */ static bool report_latency(struct trace_array *tr, u64 delta) { if (tracing_thresh) { if (delta < tracing_thresh) return false; } else { if (delta <= tr->max_latency) return false; } return true; } static void probe_wakeup_migrate_task(void *ignore, struct task_struct *task, int cpu) { if (task != wakeup_task) return; wakeup_current_cpu = cpu; } static void tracing_sched_switch_trace(struct trace_array *tr, struct task_struct *prev, struct task_struct *next, unsigned long flags, int pc) { struct trace_event_call *call = &event_context_switch; struct ring_buffer *buffer = tr->trace_buffer.buffer; struct ring_buffer_event *event; struct ctx_switch_entry *entry; event = trace_buffer_lock_reserve(buffer, TRACE_CTX, sizeof(*entry), flags, pc); if (!event) return; entry = ring_buffer_event_data(event); entry->prev_pid = prev->pid; entry->prev_prio = prev->prio; entry->prev_state = task_state_index(prev); entry->next_pid = next->pid; entry->next_prio = next->prio; entry->next_state = task_state_index(next); entry->next_cpu = task_cpu(next); if (!call_filter_check_discard(call, entry, buffer, event)) trace_buffer_unlock_commit(tr, buffer, event, flags, pc); } static void tracing_sched_wakeup_trace(struct trace_array *tr, struct task_struct *wakee, struct task_struct *curr, unsigned long flags, int pc) { struct trace_event_call *call = &event_wakeup; struct ring_buffer_event *event; struct ctx_switch_entry *entry; struct ring_buffer *buffer = tr->trace_buffer.buffer; event = trace_buffer_lock_reserve(buffer, TRACE_WAKE, sizeof(*entry), flags, pc); if (!event) return; entry = ring_buffer_event_data(event); entry->prev_pid = curr->pid; entry->prev_prio = curr->prio; entry->prev_state = task_state_index(curr); entry->next_pid = wakee->pid; entry->next_prio = wakee->prio; entry->next_state = task_state_index(wakee); entry->next_cpu = task_cpu(wakee); if (!call_filter_check_discard(call, entry, buffer, event)) trace_buffer_unlock_commit(tr, buffer, event, flags, pc); } static void notrace probe_wakeup_sched_switch(void *ignore, bool preempt, struct task_struct *prev, struct task_struct *next) { struct trace_array_cpu *data; u64 T0, T1, delta; unsigned long flags; long disabled; int cpu; int pc; tracing_record_cmdline(prev); if (unlikely(!tracer_enabled)) return; /* * When we start a new trace, we set wakeup_task to NULL * and then set tracer_enabled = 1. We want to make sure * that another CPU does not see the tracer_enabled = 1 * and the wakeup_task with an older task, that might * actually be the same as next. */ smp_rmb(); if (next != wakeup_task) return; pc = preempt_count(); /* disable local data, not wakeup_cpu data */ cpu = raw_smp_processor_id(); disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); if (likely(disabled != 1)) goto out; local_irq_save(flags); arch_spin_lock(&wakeup_lock); /* We could race with grabbing wakeup_lock */ if (unlikely(!tracer_enabled || next != wakeup_task)) goto out_unlock; /* The task we are waiting for is waking up */ data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); __trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, flags, pc); tracing_sched_switch_trace(wakeup_trace, prev, next, flags, pc); T0 = data->preempt_timestamp; T1 = ftrace_now(cpu); delta = T1-T0; if (!report_latency(wakeup_trace, delta)) goto out_unlock; if (likely(!is_tracing_stopped())) { wakeup_trace->max_latency = delta; update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); } out_unlock: __wakeup_reset(wakeup_trace); arch_spin_unlock(&wakeup_lock); local_irq_restore(flags); out: atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); } static void __wakeup_reset(struct trace_array *tr) { wakeup_cpu = -1; wakeup_prio = -1; tracing_dl = 0; if (wakeup_task) put_task_struct(wakeup_task); wakeup_task = NULL; } static void wakeup_reset(struct trace_array *tr) { unsigned long flags; tracing_reset_online_cpus(&tr->trace_buffer); local_irq_save(flags); arch_spin_lock(&wakeup_lock); __wakeup_reset(tr); arch_spin_unlock(&wakeup_lock); local_irq_restore(flags); } static void probe_wakeup(void *ignore, struct task_struct *p) { struct trace_array_cpu *data; int cpu = smp_processor_id(); unsigned long flags; long disabled; int pc; if (likely(!tracer_enabled)) return; tracing_record_cmdline(p); tracing_record_cmdline(current); /* * Semantic is like this: * - wakeup tracer handles all tasks in the system, independently * from their scheduling class; * - wakeup_rt tracer handles tasks belonging to sched_dl and * sched_rt class; * - wakeup_dl handles tasks belonging to sched_dl class only. */ if (tracing_dl || (wakeup_dl && !dl_task(p)) || (wakeup_rt && !dl_task(p) && !rt_task(p)) || (!dl_task(p) && (p->prio >= wakeup_prio || p->prio >= current->prio))) return; pc = preempt_count(); disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); if (unlikely(disabled != 1)) goto out; /* interrupts should be off from try_to_wake_up */ arch_spin_lock(&wakeup_lock); /* check for races. */ if (!tracer_enabled || tracing_dl || (!dl_task(p) && p->prio >= wakeup_prio)) goto out_locked; /* reset the trace */ __wakeup_reset(wakeup_trace); wakeup_cpu = task_cpu(p); wakeup_current_cpu = wakeup_cpu; wakeup_prio = p->prio; /* * Once you start tracing a -deadline task, don't bother tracing * another task until the first one wakes up. */ if (dl_task(p)) tracing_dl = 1; else tracing_dl = 0; wakeup_task = p; get_task_struct(wakeup_task); local_save_flags(flags); data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); data->preempt_timestamp = ftrace_now(cpu); tracing_sched_wakeup_trace(wakeup_trace, p, current, flags, pc); /* * We must be careful in using CALLER_ADDR2. But since wake_up * is not called by an assembly function (where as schedule is) * it should be safe to use it here. */ __trace_function(wakeup_trace, CALLER_ADDR1, CALLER_ADDR2, flags, pc); out_locked: arch_spin_unlock(&wakeup_lock); out: atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); } static void start_wakeup_tracer(struct trace_array *tr) { int ret; ret = register_trace_sched_wakeup(probe_wakeup, NULL); if (ret) { pr_info("wakeup trace: Couldn't activate tracepoint" " probe to kernel_sched_wakeup\n"); return; } ret = register_trace_sched_wakeup_new(probe_wakeup, NULL); if (ret) { pr_info("wakeup trace: Couldn't activate tracepoint" " probe to kernel_sched_wakeup_new\n"); goto fail_deprobe; } ret = register_trace_sched_switch(probe_wakeup_sched_switch, NULL); if (ret) { pr_info("sched trace: Couldn't activate tracepoint" " probe to kernel_sched_switch\n"); goto fail_deprobe_wake_new; } ret = register_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); if (ret) { pr_info("wakeup trace: Couldn't activate tracepoint" " probe to kernel_sched_migrate_task\n"); return; } wakeup_reset(tr); /* * Don't let the tracer_enabled = 1 show up before * the wakeup_task is reset. This may be overkill since * wakeup_reset does a spin_unlock after setting the * wakeup_task to NULL, but I want to be safe. * This is a slow path anyway. */ smp_wmb(); if (start_func_tracer(tr, is_graph(tr))) printk(KERN_ERR "failed to start wakeup tracer\n"); return; fail_deprobe_wake_new: unregister_trace_sched_wakeup_new(probe_wakeup, NULL); fail_deprobe: unregister_trace_sched_wakeup(probe_wakeup, NULL); } static void stop_wakeup_tracer(struct trace_array *tr) { tracer_enabled = 0; stop_func_tracer(tr, is_graph(tr)); unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL); unregister_trace_sched_wakeup_new(probe_wakeup, NULL); unregister_trace_sched_wakeup(probe_wakeup, NULL); unregister_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); } static bool wakeup_busy; static int __wakeup_tracer_init(struct trace_array *tr) { save_flags = tr->trace_flags; /* non overwrite screws up the latency tracers */ set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); tr->max_latency = 0; wakeup_trace = tr; ftrace_init_array_ops(tr, wakeup_tracer_call); start_wakeup_tracer(tr); wakeup_busy = true; return 0; } static int wakeup_tracer_init(struct trace_array *tr) { if (wakeup_busy) return -EBUSY; wakeup_dl = 0; wakeup_rt = 0; return __wakeup_tracer_init(tr); } static int wakeup_rt_tracer_init(struct trace_array *tr) { if (wakeup_busy) return -EBUSY; wakeup_dl = 0; wakeup_rt = 1; return __wakeup_tracer_init(tr); } static int wakeup_dl_tracer_init(struct trace_array *tr) { if (wakeup_busy) return -EBUSY; wakeup_dl = 1; wakeup_rt = 0; return __wakeup_tracer_init(tr); } static void wakeup_tracer_reset(struct trace_array *tr) { int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; stop_wakeup_tracer(tr); /* make sure we put back any tasks we are tracing */ wakeup_reset(tr); set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); ftrace_reset_array_ops(tr); wakeup_busy = false; } static void wakeup_tracer_start(struct trace_array *tr) { wakeup_reset(tr); tracer_enabled = 1; } static void wakeup_tracer_stop(struct trace_array *tr) { tracer_enabled = 0; } static struct tracer wakeup_tracer __read_mostly = { .name = "wakeup", .init = wakeup_tracer_init, .reset = wakeup_tracer_reset, .start = wakeup_tracer_start, .stop = wakeup_tracer_stop, .print_max = true, .print_header = wakeup_print_header, .print_line = wakeup_print_line, .flag_changed = wakeup_flag_changed, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_wakeup, #endif .open = wakeup_trace_open, .close = wakeup_trace_close, .allow_instances = true, .use_max_tr = true, }; static struct tracer wakeup_rt_tracer __read_mostly = { .name = "wakeup_rt", .init = wakeup_rt_tracer_init, .reset = wakeup_tracer_reset, .start = wakeup_tracer_start, .stop = wakeup_tracer_stop, .print_max = true, .print_header = wakeup_print_header, .print_line = wakeup_print_line, .flag_changed = wakeup_flag_changed, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_wakeup, #endif .open = wakeup_trace_open, .close = wakeup_trace_close, .allow_instances = true, .use_max_tr = true, }; static struct tracer wakeup_dl_tracer __read_mostly = { .name = "wakeup_dl", .init = wakeup_dl_tracer_init, .reset = wakeup_tracer_reset, .start = wakeup_tracer_start, .stop = wakeup_tracer_stop, .print_max = true, .print_header = wakeup_print_header, .print_line = wakeup_print_line, .flag_changed = wakeup_flag_changed, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_wakeup, #endif .open = wakeup_trace_open, .close = wakeup_trace_close, .allow_instances = true, .use_max_tr = true, }; __init static int init_wakeup_tracer(void) { int ret; ret = register_tracer(&wakeup_tracer); if (ret) return ret; ret = register_tracer(&wakeup_rt_tracer); if (ret) return ret; ret = register_tracer(&wakeup_dl_tracer); if (ret) return ret; return 0; } core_initcall(init_wakeup_tracer);
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