// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org> */ #define _GNU_SOURCE #include <getopt.h> #include <stdlib.h> #include <string.h> #include <signal.h> #include <unistd.h> #include <stdio.h> #include <time.h> #include <errno.h> #include <sched.h> #include <pthread.h> #include "utils.h" #include "osnoise.h" #include "timerlat.h" #include "timerlat_aa.h" #include "timerlat_u.h" struct timerlat_top_params { char *cpus; cpu_set_t monitored_cpus; char *trace_output; char *cgroup_name; unsigned long long runtime; long long stop_us; long long stop_total_us; long long timerlat_period_us; long long print_stack; int sleep_time; int output_divisor; int duration; int quiet; int set_sched; int dma_latency; int no_aa; int aa_only; int dump_tasks; int cgroup; int hk_cpus; int user_top; cpu_set_t hk_cpu_set; struct sched_attr sched_param; struct trace_events *events; }; struct timerlat_top_cpu { int irq_count; int thread_count; int user_count; unsigned long long cur_irq; unsigned long long min_irq; unsigned long long sum_irq; unsigned long long max_irq; unsigned long long cur_thread; unsigned long long min_thread; unsigned long long sum_thread; unsigned long long max_thread; unsigned long long cur_user; unsigned long long min_user; unsigned long long sum_user; unsigned long long max_user; }; struct timerlat_top_data { struct timerlat_top_cpu *cpu_data; int nr_cpus; }; /* * timerlat_free_top - free runtime data */ static void timerlat_free_top(struct timerlat_top_data *data) { free(data->cpu_data); free(data); } /* * timerlat_alloc_histogram - alloc runtime data */ static struct timerlat_top_data *timerlat_alloc_top(int nr_cpus) { struct timerlat_top_data *data; int cpu; data = calloc(1, sizeof(*data)); if (!data) return NULL; data->nr_cpus = nr_cpus; /* one set of histograms per CPU */ data->cpu_data = calloc(1, sizeof(*data->cpu_data) * nr_cpus); if (!data->cpu_data) goto cleanup; /* set the min to max */ for (cpu = 0; cpu < nr_cpus; cpu++) { data->cpu_data[cpu].min_irq = ~0; data->cpu_data[cpu].min_thread = ~0; data->cpu_data[cpu].min_user = ~0; } return data; cleanup: timerlat_free_top(data); return NULL; } /* * timerlat_hist_update - record a new timerlat occurent on cpu, updating data */ static void timerlat_top_update(struct osnoise_tool *tool, int cpu, unsigned long long thread, unsigned long long latency) { struct timerlat_top_data *data = tool->data; struct timerlat_top_cpu *cpu_data = &data->cpu_data[cpu]; if (!thread) { cpu_data->irq_count++; cpu_data->cur_irq = latency; update_min(&cpu_data->min_irq, &latency); update_sum(&cpu_data->sum_irq, &latency); update_max(&cpu_data->max_irq, &latency); } else if (thread == 1) { cpu_data->thread_count++; cpu_data->cur_thread = latency; update_min(&cpu_data->min_thread, &latency); update_sum(&cpu_data->sum_thread, &latency); update_max(&cpu_data->max_thread, &latency); } else { cpu_data->user_count++; cpu_data->cur_user = latency; update_min(&cpu_data->min_user, &latency); update_sum(&cpu_data->sum_user, &latency); update_max(&cpu_data->max_user, &latency); } } /* * timerlat_top_handler - this is the handler for timerlat tracer events */ static int timerlat_top_handler(struct trace_seq *s, struct tep_record *record, struct tep_event *event, void *context) { struct trace_instance *trace = context; struct timerlat_top_params *params; unsigned long long latency, thread; struct osnoise_tool *top; int cpu = record->cpu; top = container_of(trace, struct osnoise_tool, trace); params = top->params; if (!params->aa_only) { tep_get_field_val(s, event, "context", record, &thread, 1); tep_get_field_val(s, event, "timer_latency", record, &latency, 1); timerlat_top_update(top, cpu, thread, latency); } return 0; } /* * timerlat_top_header - print the header of the tool output */ static void timerlat_top_header(struct osnoise_tool *top) { struct timerlat_top_params *params = top->params; struct trace_seq *s = top->trace.seq; char duration[26]; get_duration(top->start_time, duration, sizeof(duration)); trace_seq_printf(s, "\033[2;37;40m"); trace_seq_printf(s, " Timer Latency "); if (params->user_top) trace_seq_printf(s, " "); trace_seq_printf(s, "\033[0;0;0m"); trace_seq_printf(s, "\n"); trace_seq_printf(s, "%-6s | IRQ Timer Latency (%s) | Thread Timer Latency (%s)", duration, params->output_divisor == 1 ? "ns" : "us", params->output_divisor == 1 ? "ns" : "us"); if (params->user_top) { trace_seq_printf(s, " | Ret user Timer Latency (%s)", params->output_divisor == 1 ? "ns" : "us"); } trace_seq_printf(s, "\n"); trace_seq_printf(s, "\033[2;30;47m"); trace_seq_printf(s, "CPU COUNT | cur min avg max | cur min avg max"); if (params->user_top) trace_seq_printf(s, " | cur min avg max"); trace_seq_printf(s, "\033[0;0;0m"); trace_seq_printf(s, "\n"); } /* * timerlat_top_print - prints the output of a given CPU */ static void timerlat_top_print(struct osnoise_tool *top, int cpu) { struct timerlat_top_params *params = top->params; struct timerlat_top_data *data = top->data; struct timerlat_top_cpu *cpu_data = &data->cpu_data[cpu]; int divisor = params->output_divisor; struct trace_seq *s = top->trace.seq; if (divisor == 0) return; /* * Skip if no data is available: is this cpu offline? */ if (!cpu_data->irq_count && !cpu_data->thread_count) return; /* * Unless trace is being lost, IRQ counter is always the max. */ trace_seq_printf(s, "%3d #%-9d |", cpu, cpu_data->irq_count); if (!cpu_data->irq_count) { trace_seq_printf(s, " - "); trace_seq_printf(s, " - "); trace_seq_printf(s, " - "); trace_seq_printf(s, " - |"); } else { trace_seq_printf(s, "%9llu ", cpu_data->cur_irq / params->output_divisor); trace_seq_printf(s, "%9llu ", cpu_data->min_irq / params->output_divisor); trace_seq_printf(s, "%9llu ", (cpu_data->sum_irq / cpu_data->irq_count) / divisor); trace_seq_printf(s, "%9llu |", cpu_data->max_irq / divisor); } if (!cpu_data->thread_count) { trace_seq_printf(s, " - "); trace_seq_printf(s, " - "); trace_seq_printf(s, " - "); trace_seq_printf(s, " -\n"); } else { trace_seq_printf(s, "%9llu ", cpu_data->cur_thread / divisor); trace_seq_printf(s, "%9llu ", cpu_data->min_thread / divisor); trace_seq_printf(s, "%9llu ", (cpu_data->sum_thread / cpu_data->thread_count) / divisor); trace_seq_printf(s, "%9llu", cpu_data->max_thread / divisor); } if (!params->user_top) { trace_seq_printf(s, "\n"); return; } trace_seq_printf(s, " |"); if (!cpu_data->user_count) { trace_seq_printf(s, " - "); trace_seq_printf(s, " - "); trace_seq_printf(s, " - "); trace_seq_printf(s, " -\n"); } else { trace_seq_printf(s, "%9llu ", cpu_data->cur_user / divisor); trace_seq_printf(s, "%9llu ", cpu_data->min_user / divisor); trace_seq_printf(s, "%9llu ", (cpu_data->sum_user / cpu_data->user_count) / divisor); trace_seq_printf(s, "%9llu\n", cpu_data->max_user / divisor); } } /* * clear_terminal - clears the output terminal */ static void clear_terminal(struct trace_seq *seq) { if (!config_debug) trace_seq_printf(seq, "\033c"); } /* * timerlat_print_stats - print data for all cpus */ static void timerlat_print_stats(struct timerlat_top_params *params, struct osnoise_tool *top) { struct trace_instance *trace = &top->trace; static int nr_cpus = -1; int i; if (params->aa_only) return; if (nr_cpus == -1) nr_cpus = sysconf(_SC_NPROCESSORS_CONF); if (!params->quiet) clear_terminal(trace->seq); timerlat_top_header(top); for (i = 0; i < nr_cpus; i++) { if (params->cpus && !CPU_ISSET(i, ¶ms->monitored_cpus)) continue; timerlat_top_print(top, i); } trace_seq_do_printf(trace->seq); trace_seq_reset(trace->seq); } /* * timerlat_top_usage - prints timerlat top usage message */ static void timerlat_top_usage(char *usage) { int i; static const char *const msg[] = { "", " usage: rtla timerlat [top] [-h] [-q] [-a us] [-d s] [-D] [-n] [-p us] [-i us] [-T us] [-s us] \\", " [[-t[=file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] [-c cpu-list] [-H cpu-list]\\", " [-P priority] [--dma-latency us] [--aa-only us] [-C[=cgroup_name]] [-u]", "", " -h/--help: print this menu", " -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit", " --aa-only us: stop if <us> latency is hit, only printing the auto analysis (reduces CPU usage)", " -p/--period us: timerlat period in us", " -i/--irq us: stop trace if the irq latency is higher than the argument in us", " -T/--thread us: stop trace if the thread latency is higher than the argument in us", " -s/--stack us: save the stack trace at the IRQ if a thread latency is higher than the argument in us", " -c/--cpus cpus: run the tracer only on the given cpus", " -H/--house-keeping cpus: run rtla control threads only on the given cpus", " -C/--cgroup[=cgroup_name]: set cgroup, if no cgroup_name is passed, the rtla's cgroup will be inherited", " -d/--duration time[m|h|d]: duration of the session in seconds", " -D/--debug: print debug info", " --dump-tasks: prints the task running on all CPUs if stop conditions are met (depends on !--no-aa)", " -t/--trace[=file]: save the stopped trace to [file|timerlat_trace.txt]", " -e/--event <sys:event>: enable the <sys:event> in the trace instance, multiple -e are allowed", " --filter <command>: enable a trace event filter to the previous -e event", " --trigger <command>: enable a trace event trigger to the previous -e event", " -n/--nano: display data in nanoseconds", " --no-aa: disable auto-analysis, reducing rtla timerlat cpu usage", " -q/--quiet print only a summary at the end", " --dma-latency us: set /dev/cpu_dma_latency latency <us> to reduce exit from idle latency", " -P/--priority o:prio|r:prio|f:prio|d:runtime:period : set scheduling parameters", " o:prio - use SCHED_OTHER with prio", " r:prio - use SCHED_RR with prio", " f:prio - use SCHED_FIFO with prio", " d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period", " in nanoseconds", " -u/--user-threads: use rtla user-space threads instead of in-kernel timerlat threads", NULL, }; if (usage) fprintf(stderr, "%s\n", usage); fprintf(stderr, "rtla timerlat top: a per-cpu summary of the timer latency (version %s)\n", VERSION); for (i = 0; msg[i]; i++) fprintf(stderr, "%s\n", msg[i]); exit(1); } /* * timerlat_top_parse_args - allocs, parse and fill the cmd line parameters */ static struct timerlat_top_params *timerlat_top_parse_args(int argc, char **argv) { struct timerlat_top_params *params; struct trace_events *tevent; long long auto_thresh; int retval; int c; params = calloc(1, sizeof(*params)); if (!params) exit(1); /* disabled by default */ params->dma_latency = -1; /* display data in microseconds */ params->output_divisor = 1000; while (1) { static struct option long_options[] = { {"auto", required_argument, 0, 'a'}, {"cpus", required_argument, 0, 'c'}, {"cgroup", optional_argument, 0, 'C'}, {"debug", no_argument, 0, 'D'}, {"duration", required_argument, 0, 'd'}, {"event", required_argument, 0, 'e'}, {"help", no_argument, 0, 'h'}, {"house-keeping", required_argument, 0, 'H'}, {"irq", required_argument, 0, 'i'}, {"nano", no_argument, 0, 'n'}, {"period", required_argument, 0, 'p'}, {"priority", required_argument, 0, 'P'}, {"quiet", no_argument, 0, 'q'}, {"stack", required_argument, 0, 's'}, {"thread", required_argument, 0, 'T'}, {"trace", optional_argument, 0, 't'}, {"user-threads", no_argument, 0, 'u'}, {"trigger", required_argument, 0, '0'}, {"filter", required_argument, 0, '1'}, {"dma-latency", required_argument, 0, '2'}, {"no-aa", no_argument, 0, '3'}, {"dump-tasks", no_argument, 0, '4'}, {"aa-only", required_argument, 0, '5'}, {0, 0, 0, 0} }; /* getopt_long stores the option index here. */ int option_index = 0; c = getopt_long(argc, argv, "a:c:C::d:De:hH:i:np:P:qs:t::T:u0:1:2:345:", long_options, &option_index); /* detect the end of the options. */ if (c == -1) break; switch (c) { case 'a': auto_thresh = get_llong_from_str(optarg); /* set thread stop to auto_thresh */ params->stop_total_us = auto_thresh; params->stop_us = auto_thresh; /* get stack trace */ params->print_stack = auto_thresh; /* set trace */ params->trace_output = "timerlat_trace.txt"; break; case '5': /* it is here because it is similar to -a */ auto_thresh = get_llong_from_str(optarg); /* set thread stop to auto_thresh */ params->stop_total_us = auto_thresh; params->stop_us = auto_thresh; /* get stack trace */ params->print_stack = auto_thresh; /* set aa_only to avoid parsing the trace */ params->aa_only = 1; break; case 'c': retval = parse_cpu_set(optarg, ¶ms->monitored_cpus); if (retval) timerlat_top_usage("\nInvalid -c cpu list\n"); params->cpus = optarg; break; case 'C': params->cgroup = 1; if (!optarg) { /* will inherit this cgroup */ params->cgroup_name = NULL; } else if (*optarg == '=') { /* skip the = */ params->cgroup_name = ++optarg; } break; case 'D': config_debug = 1; break; case 'd': params->duration = parse_seconds_duration(optarg); if (!params->duration) timerlat_top_usage("Invalid -D duration\n"); break; case 'e': tevent = trace_event_alloc(optarg); if (!tevent) { err_msg("Error alloc trace event"); exit(EXIT_FAILURE); } if (params->events) tevent->next = params->events; params->events = tevent; break; case 'h': case '?': timerlat_top_usage(NULL); break; case 'H': params->hk_cpus = 1; retval = parse_cpu_set(optarg, ¶ms->hk_cpu_set); if (retval) { err_msg("Error parsing house keeping CPUs\n"); exit(EXIT_FAILURE); } break; case 'i': params->stop_us = get_llong_from_str(optarg); break; case 'n': params->output_divisor = 1; break; case 'p': params->timerlat_period_us = get_llong_from_str(optarg); if (params->timerlat_period_us > 1000000) timerlat_top_usage("Period longer than 1 s\n"); break; case 'P': retval = parse_prio(optarg, ¶ms->sched_param); if (retval == -1) timerlat_top_usage("Invalid -P priority"); params->set_sched = 1; break; case 'q': params->quiet = 1; break; case 's': params->print_stack = get_llong_from_str(optarg); break; case 'T': params->stop_total_us = get_llong_from_str(optarg); break; case 't': if (optarg) /* skip = */ params->trace_output = &optarg[1]; else params->trace_output = "timerlat_trace.txt"; break; case 'u': params->user_top = true; break; case '0': /* trigger */ if (params->events) { retval = trace_event_add_trigger(params->events, optarg); if (retval) { err_msg("Error adding trigger %s\n", optarg); exit(EXIT_FAILURE); } } else { timerlat_top_usage("--trigger requires a previous -e\n"); } break; case '1': /* filter */ if (params->events) { retval = trace_event_add_filter(params->events, optarg); if (retval) { err_msg("Error adding filter %s\n", optarg); exit(EXIT_FAILURE); } } else { timerlat_top_usage("--filter requires a previous -e\n"); } break; case '2': /* dma-latency */ params->dma_latency = get_llong_from_str(optarg); if (params->dma_latency < 0 || params->dma_latency > 10000) { err_msg("--dma-latency needs to be >= 0 and < 10000"); exit(EXIT_FAILURE); } break; case '3': /* no-aa */ params->no_aa = 1; break; case '4': params->dump_tasks = 1; break; default: timerlat_top_usage("Invalid option"); } } if (geteuid()) { err_msg("rtla needs root permission\n"); exit(EXIT_FAILURE); } /* * Auto analysis only happens if stop tracing, thus: */ if (!params->stop_us && !params->stop_total_us) params->no_aa = 1; if (params->no_aa && params->aa_only) timerlat_top_usage("--no-aa and --aa-only are mutually exclusive!"); return params; } /* * timerlat_top_apply_config - apply the top configs to the initialized tool */ static int timerlat_top_apply_config(struct osnoise_tool *top, struct timerlat_top_params *params) { int retval; int i; if (!params->sleep_time) params->sleep_time = 1; if (params->cpus) { retval = osnoise_set_cpus(top->context, params->cpus); if (retval) { err_msg("Failed to apply CPUs config\n"); goto out_err; } } else { for (i = 0; i < sysconf(_SC_NPROCESSORS_CONF); i++) CPU_SET(i, ¶ms->monitored_cpus); } if (params->stop_us) { retval = osnoise_set_stop_us(top->context, params->stop_us); if (retval) { err_msg("Failed to set stop us\n"); goto out_err; } } if (params->stop_total_us) { retval = osnoise_set_stop_total_us(top->context, params->stop_total_us); if (retval) { err_msg("Failed to set stop total us\n"); goto out_err; } } if (params->timerlat_period_us) { retval = osnoise_set_timerlat_period_us(top->context, params->timerlat_period_us); if (retval) { err_msg("Failed to set timerlat period\n"); goto out_err; } } if (params->print_stack) { retval = osnoise_set_print_stack(top->context, params->print_stack); if (retval) { err_msg("Failed to set print stack\n"); goto out_err; } } if (params->hk_cpus) { retval = sched_setaffinity(getpid(), sizeof(params->hk_cpu_set), ¶ms->hk_cpu_set); if (retval == -1) { err_msg("Failed to set rtla to the house keeping CPUs\n"); goto out_err; } } else if (params->cpus) { /* * Even if the user do not set a house-keeping CPU, try to * move rtla to a CPU set different to the one where the user * set the workload to run. * * No need to check results as this is an automatic attempt. */ auto_house_keeping(¶ms->monitored_cpus); } if (params->user_top) { retval = osnoise_set_workload(top->context, 0); if (retval) { err_msg("Failed to set OSNOISE_WORKLOAD option\n"); goto out_err; } } return 0; out_err: return -1; } /* * timerlat_init_top - initialize a timerlat top tool with parameters */ static struct osnoise_tool *timerlat_init_top(struct timerlat_top_params *params) { struct osnoise_tool *top; int nr_cpus; nr_cpus = sysconf(_SC_NPROCESSORS_CONF); top = osnoise_init_tool("timerlat_top"); if (!top) return NULL; top->data = timerlat_alloc_top(nr_cpus); if (!top->data) goto out_err; top->params = params; tep_register_event_handler(top->trace.tep, -1, "ftrace", "timerlat", timerlat_top_handler, top); return top; out_err: osnoise_destroy_tool(top); return NULL; } static int stop_tracing; static void stop_top(int sig) { stop_tracing = 1; } /* * timerlat_top_set_signals - handles the signal to stop the tool */ static void timerlat_top_set_signals(struct timerlat_top_params *params) { signal(SIGINT, stop_top); if (params->duration) { signal(SIGALRM, stop_top); alarm(params->duration); } } int timerlat_top_main(int argc, char *argv[]) { struct timerlat_top_params *params; struct osnoise_tool *record = NULL; struct timerlat_u_params params_u; struct osnoise_tool *top = NULL; struct osnoise_tool *aa = NULL; struct trace_instance *trace; int dma_latency_fd = -1; pthread_t timerlat_u; int return_value = 1; char *max_lat; int retval; params = timerlat_top_parse_args(argc, argv); if (!params) exit(1); top = timerlat_init_top(params); if (!top) { err_msg("Could not init osnoise top\n"); goto out_exit; } retval = timerlat_top_apply_config(top, params); if (retval) { err_msg("Could not apply config\n"); goto out_free; } trace = &top->trace; retval = enable_timerlat(trace); if (retval) { err_msg("Failed to enable timerlat tracer\n"); goto out_free; } if (params->set_sched) { retval = set_comm_sched_attr("timerlat/", ¶ms->sched_param); if (retval) { err_msg("Failed to set sched parameters\n"); goto out_free; } } if (params->cgroup && !params->user_top) { retval = set_comm_cgroup("timerlat/", params->cgroup_name); if (!retval) { err_msg("Failed to move threads to cgroup\n"); goto out_free; } } if (params->dma_latency >= 0) { dma_latency_fd = set_cpu_dma_latency(params->dma_latency); if (dma_latency_fd < 0) { err_msg("Could not set /dev/cpu_dma_latency.\n"); goto out_free; } } if (params->trace_output) { record = osnoise_init_trace_tool("timerlat"); if (!record) { err_msg("Failed to enable the trace instance\n"); goto out_free; } if (params->events) { retval = trace_events_enable(&record->trace, params->events); if (retval) goto out_top; } } if (!params->no_aa) { if (params->aa_only) { /* as top is not used for display, use it for aa */ aa = top; } else { /* otherwise, a new instance is needed */ aa = osnoise_init_tool("timerlat_aa"); if (!aa) goto out_top; } retval = timerlat_aa_init(aa, params->dump_tasks); if (retval) { err_msg("Failed to enable the auto analysis instance\n"); goto out_top; } /* if it is re-using the main instance, there is no need to start it */ if (aa != top) { retval = enable_timerlat(&aa->trace); if (retval) { err_msg("Failed to enable timerlat tracer\n"); goto out_top; } } } /* * Start the tracers here, after having set all instances. * * Let the trace instance start first for the case of hitting a stop * tracing while enabling other instances. The trace instance is the * one with most valuable information. */ if (params->trace_output) trace_instance_start(&record->trace); if (!params->no_aa && aa != top) trace_instance_start(&aa->trace); trace_instance_start(trace); top->start_time = time(NULL); timerlat_top_set_signals(params); if (params->user_top) { /* rtla asked to stop */ params_u.should_run = 1; /* all threads left */ params_u.stopped_running = 0; params_u.set = ¶ms->monitored_cpus; if (params->set_sched) params_u.sched_param = ¶ms->sched_param; else params_u.sched_param = NULL; params_u.cgroup_name = params->cgroup_name; retval = pthread_create(&timerlat_u, NULL, timerlat_u_dispatcher, ¶ms_u); if (retval) err_msg("Error creating timerlat user-space threads\n"); } while (!stop_tracing) { sleep(params->sleep_time); if (params->aa_only && !trace_is_off(&top->trace, &record->trace)) continue; retval = tracefs_iterate_raw_events(trace->tep, trace->inst, NULL, 0, collect_registered_events, trace); if (retval < 0) { err_msg("Error iterating on events\n"); goto out_top; } if (!params->quiet) timerlat_print_stats(params, top); if (trace_is_off(&top->trace, &record->trace)) break; /* is there still any user-threads ? */ if (params->user_top) { if (params_u.stopped_running) { debug_msg("timerlat user space threads stopped!\n"); break; } } } if (params->user_top && !params_u.stopped_running) { params_u.should_run = 0; sleep(1); } timerlat_print_stats(params, top); return_value = 0; if (trace_is_off(&top->trace, &record->trace)) { printf("rtla timerlat hit stop tracing\n"); if (!params->no_aa) timerlat_auto_analysis(params->stop_us, params->stop_total_us); if (params->trace_output) { printf(" Saving trace to %s\n", params->trace_output); save_trace_to_file(record->trace.inst, params->trace_output); } } else if (params->aa_only) { /* * If the trace did not stop with --aa-only, at least print the * max known latency. */ max_lat = tracefs_instance_file_read(trace->inst, "tracing_max_latency", NULL); if (max_lat) { printf(" Max latency was %s\n", max_lat); free(max_lat); } } out_top: timerlat_aa_destroy(); if (dma_latency_fd >= 0) close(dma_latency_fd); trace_events_destroy(&record->trace, params->events); params->events = NULL; out_free: timerlat_free_top(top->data); if (aa && aa != top) osnoise_destroy_tool(aa); osnoise_destroy_tool(record); osnoise_destroy_tool(top); free(params); out_exit: exit(return_value); }