--- zzzz-none-000/linux-3.10.107/kernel/trace/trace_sched_wakeup.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/kernel/trace/trace_sched_wakeup.c 2021-02-04 17:41:59.000000000 +0000 @@ -10,12 +10,11 @@ * Copyright (C) 2004 Nadia Yvette Chambers */ #include -#include -#include #include #include #include #include +#include #include #include "trace.h" @@ -27,37 +26,36 @@ 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 wakeup_graph_entry(struct ftrace_graph_ent *trace); -static void wakeup_graph_return(struct ftrace_graph_ret *trace); static int save_flags; -static bool function_enabled; - -#define TRACE_DISPLAY_GRAPH 1 -static struct tracer_opt trace_opts[] = { #ifdef CONFIG_FUNCTION_GRAPH_TRACER - /* display latency trace as call graph */ - { TRACER_OPT(display-graph, TRACE_DISPLAY_GRAPH) }, +static int wakeup_display_graph(struct trace_array *tr, int set); +# define is_graph(tr) ((tr)->trace_flags & TRACE_ITER_DISPLAY_GRAPH) +#else +static inline int wakeup_display_graph(struct trace_array *tr, int set) +{ + return 0; +} +# define is_graph(tr) false #endif - { } /* Empty entry */ -}; - -static struct tracer_flags tracer_flags = { - .val = 0, - .opts = trace_opts, -}; -#define is_graph() (tracer_flags.val & TRACE_DISPLAY_GRAPH) #ifdef CONFIG_FUNCTION_TRACER +static int wakeup_graph_entry(struct ftrace_graph_ent *trace); +static void wakeup_graph_return(struct ftrace_graph_ret *trace); + +static bool function_enabled; + /* * Prologue for the wakeup function tracers. * @@ -128,26 +126,19 @@ preempt_enable_notrace(); } -static struct ftrace_ops trace_ops __read_mostly = -{ - .func = wakeup_tracer_call, - .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE, -}; -#endif /* CONFIG_FUNCTION_TRACER */ - -static int register_wakeup_function(int graph, int set) +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 && !(trace_flags & TRACE_ITER_FUNCTION))) + if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION))) return 0; if (graph) ret = register_ftrace_graph(&wakeup_graph_return, &wakeup_graph_entry); else - ret = register_ftrace_function(&trace_ops); + ret = register_ftrace_function(tr->ops); if (!ret) function_enabled = true; @@ -155,7 +146,7 @@ return ret; } -static void unregister_wakeup_function(int graph) +static void unregister_wakeup_function(struct trace_array *tr, int graph) { if (!function_enabled) return; @@ -163,32 +154,54 @@ if (graph) unregister_ftrace_graph(); else - unregister_ftrace_function(&trace_ops); + unregister_ftrace_function(tr->ops); function_enabled = false; } -static void wakeup_function_set(int set) +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(is_graph(), 1); + register_wakeup_function(tr, is_graph(tr), 1); else - unregister_wakeup_function(is_graph()); + unregister_wakeup_function(tr, is_graph(tr)); + return 1; } +#else +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 /* CONFIG_FUNCTION_TRACER */ -static int wakeup_flag_changed(struct tracer *tracer, u32 mask, int set) +static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set) { - if (mask & TRACE_ITER_FUNCTION) - wakeup_function_set(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(int graph) +static int start_func_tracer(struct trace_array *tr, int graph) { int ret; - ret = register_wakeup_function(graph, 0); + ret = register_wakeup_function(tr, graph, 0); if (!ret && tracing_is_enabled()) tracer_enabled = 1; @@ -198,29 +211,25 @@ return ret; } -static void stop_func_tracer(int graph) +static void stop_func_tracer(struct trace_array *tr, int graph) { tracer_enabled = 0; - unregister_wakeup_function(graph); + unregister_wakeup_function(tr, graph); } #ifdef CONFIG_FUNCTION_GRAPH_TRACER -static int wakeup_set_flag(u32 old_flags, u32 bit, int set) +static int wakeup_display_graph(struct trace_array *tr, int set) { - - if (!(bit & TRACE_DISPLAY_GRAPH)) - return -EINVAL; - - if (!(is_graph() ^ set)) + if (!(is_graph(tr) ^ set)) return 0; - stop_func_tracer(!set); + stop_func_tracer(tr, !set); wakeup_reset(wakeup_trace); - tracing_max_latency = 0; + tr->max_latency = 0; - return start_func_tracer(set); + return start_func_tracer(tr, set); } static int wakeup_graph_entry(struct ftrace_graph_ent *trace) @@ -261,7 +270,7 @@ static void wakeup_trace_open(struct trace_iterator *iter) { - if (is_graph()) + if (is_graph(iter->tr)) graph_trace_open(iter); } @@ -281,7 +290,7 @@ * In graph mode call the graph tracer output function, * otherwise go with the TRACE_FN event handler */ - if (is_graph()) + if (is_graph(iter->tr)) return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS); return TRACE_TYPE_UNHANDLED; @@ -289,7 +298,7 @@ static void wakeup_print_header(struct seq_file *s) { - if (is_graph()) + if (is_graph(wakeup_trace)) print_graph_headers_flags(s, GRAPH_TRACER_FLAGS); else trace_default_header(s); @@ -300,7 +309,7 @@ unsigned long ip, unsigned long parent_ip, unsigned long flags, int pc) { - if (is_graph()) + if (is_graph(tr)) trace_graph_function(tr, ip, parent_ip, flags, pc); else trace_function(tr, ip, parent_ip, flags, pc); @@ -308,26 +317,20 @@ #else #define __trace_function trace_function -static int wakeup_set_flag(u32 old_flags, u32 bit, int set) -{ - return -EINVAL; -} - -static int wakeup_graph_entry(struct ftrace_graph_ent *trace) -{ - return -1; -} - static enum print_line_t wakeup_print_line(struct trace_iterator *iter) { return TRACE_TYPE_UNHANDLED; } -static void wakeup_graph_return(struct ftrace_graph_ret *trace) { } static void wakeup_trace_open(struct trace_iterator *iter) { } static void wakeup_trace_close(struct trace_iterator *iter) { } #ifdef CONFIG_FUNCTION_TRACER +static int wakeup_graph_entry(struct ftrace_graph_ent *trace) +{ + return -1; +} +static void wakeup_graph_return(struct ftrace_graph_ret *trace) { } static void wakeup_print_header(struct seq_file *s) { trace_default_header(s); @@ -343,16 +346,16 @@ /* * Should this new latency be reported/recorded? */ -static int report_latency(cycle_t delta) +static bool report_latency(struct trace_array *tr, cycle_t delta) { if (tracing_thresh) { if (delta < tracing_thresh) - return 0; + return false; } else { - if (delta <= tracing_max_latency) - return 0; + if (delta <= tr->max_latency) + return false; } - return 1; + return true; } static void @@ -364,8 +367,64 @@ 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 = prev->state; + entry->next_pid = next->pid; + entry->next_prio = next->prio; + entry->next_state = next->state; + 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 = curr->state; + entry->next_pid = wakee->pid; + entry->next_prio = wakee->prio; + entry->next_state = wakee->state; + 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, +probe_wakeup_sched_switch(void *ignore, bool preempt, struct task_struct *prev, struct task_struct *next) { struct trace_array_cpu *data; @@ -417,11 +476,11 @@ T1 = ftrace_now(cpu); delta = T1-T0; - if (!report_latency(delta)) + if (!report_latency(wakeup_trace, delta)) goto out_unlock; if (likely(!is_tracing_stopped())) { - tracing_max_latency = delta; + wakeup_trace->max_latency = delta; update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); } @@ -437,6 +496,7 @@ { wakeup_cpu = -1; wakeup_prio = -1; + tracing_dl = 0; if (wakeup_task) put_task_struct(wakeup_task); @@ -458,7 +518,7 @@ } static void -probe_wakeup(void *ignore, struct task_struct *p, int success) +probe_wakeup(void *ignore, struct task_struct *p) { struct trace_array_cpu *data; int cpu = smp_processor_id(); @@ -472,9 +532,17 @@ tracing_record_cmdline(p); tracing_record_cmdline(current); - if ((wakeup_rt && !rt_task(p)) || - p->prio >= wakeup_prio || - p->prio >= current->prio) + /* + * 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(); @@ -486,7 +554,8 @@ arch_spin_lock(&wakeup_lock); /* check for races. */ - if (!tracer_enabled || p->prio >= wakeup_prio) + if (!tracer_enabled || tracing_dl || + (!dl_task(p) && p->prio >= wakeup_prio)) goto out_locked; /* reset the trace */ @@ -496,6 +565,15 @@ 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); @@ -561,7 +639,7 @@ */ smp_wmb(); - if (start_func_tracer(is_graph())) + if (start_func_tracer(tr, is_graph(tr))) printk(KERN_ERR "failed to start wakeup tracer\n"); return; @@ -574,39 +652,62 @@ static void stop_wakeup_tracer(struct trace_array *tr) { tracer_enabled = 0; - stop_func_tracer(is_graph()); + 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 = trace_flags; + 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); - tracing_max_latency = 0; + 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; @@ -618,6 +719,8 @@ 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) @@ -641,14 +744,13 @@ .print_max = true, .print_header = wakeup_print_header, .print_line = wakeup_print_line, - .flags = &tracer_flags, - .set_flag = wakeup_set_flag, .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, }; @@ -659,12 +761,29 @@ .reset = wakeup_tracer_reset, .start = wakeup_tracer_start, .stop = wakeup_tracer_stop, - .wait_pipe = poll_wait_pipe, .print_max = true, .print_header = wakeup_print_header, .print_line = wakeup_print_line, - .flags = &tracer_flags, - .set_flag = wakeup_set_flag, + .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, @@ -686,6 +805,10 @@ if (ret) return ret; + ret = register_tracer(&wakeup_dl_tracer); + if (ret) + return ret; + return 0; } core_initcall(init_wakeup_tracer);