// SPDX-License-Identifier: GPL-2.0/* * Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org> */#define _GNU_SOURCE#include <sys/types.h>#include <sys/stat.h>#include <pthread.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <errno.h>#include <fcntl.h>#include <stdio.h>#include <sched.h> #include "timerlat.h" #define DEFAULT_TIMERLAT_PERIOD	1000			/* 1ms */ /* * timerlat_apply_config - apply common configs to the initialized tool */inttimerlat_apply_config(struct osnoise_tool *tool, struct timerlat_params *params){	int retval, i; 	if (!params->sleep_time)		params->sleep_time = 1; 	retval = osnoise_set_cpus(tool->context, params->cpus ? params->cpus : "all");	if (retval) {		err_msg("Failed to apply CPUs config\n");		goto out_err;	} 	if (!params->cpus) {		for (i = 0; i < sysconf(_SC_NPROCESSORS_CONF); i++)			CPU_SET(i, &params->monitored_cpus);	} 	if (params->mode != TRACING_MODE_BPF) {		/*		 * In tracefs and mixed mode, timerlat tracer handles stopping		 * on threshold		 */		retval = osnoise_set_stop_us(tool->context, params->stop_us);		if (retval) {			err_msg("Failed to set stop us\n");			goto out_err;		} 		retval = osnoise_set_stop_total_us(tool->context, params->stop_total_us);		if (retval) {			err_msg("Failed to set stop total us\n");			goto out_err;		}	}  	retval = osnoise_set_timerlat_period_us(tool->context,						params->timerlat_period_us ?						params->timerlat_period_us :						DEFAULT_TIMERLAT_PERIOD);	if (retval) {		err_msg("Failed to set timerlat period\n");		goto out_err;	}  	retval = osnoise_set_print_stack(tool->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),					   &params->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(&params->monitored_cpus);	} 	/*	 * If the user did not specify a type of thread, try user-threads first.	 * Fall back to kernel threads otherwise.	 */	if (!params->kernel_workload && !params->user_data) {		retval = tracefs_file_exists(NULL, "osnoise/per_cpu/cpu0/timerlat_fd");		if (retval) {			debug_msg("User-space interface detected, setting user-threads\n");			params->user_workload = 1;			params->user_data = 1;		} else {			debug_msg("User-space interface not detected, setting kernel-threads\n");			params->kernel_workload = 1;		}	} 	/*	 * Set workload according to type of thread if the kernel supports it.	 * On kernels without support, user threads will have already failed	 * on missing timerlat_fd, and kernel threads do not need it.	 */	retval = osnoise_set_workload(tool->context, params->kernel_workload);	if (retval < -1) {		err_msg("Failed to set OSNOISE_WORKLOAD option\n");		goto out_err;	} 	return 0; out_err:	return -1;} static void timerlat_usage(int err){	int i; 	static const char * const msg[] = {		"",		"timerlat version " VERSION,		"",		"  usage: [rtla] timerlat [MODE] ...",		"",		"  modes:",		"     top   - prints the summary from timerlat tracer",		"     hist  - prints a histogram of timer latencies",		"",		"if no MODE is given, the top mode is called, passing the arguments",		NULL,	}; 	for (i = 0; msg[i]; i++)		fprintf(stderr, "%s\n", msg[i]);	exit(err);} int timerlat_main(int argc, char *argv[]){	if (argc == 0)		goto usage; 	/*	 * if timerlat was called without any argument, run the	 * default cmdline.	 */	if (argc == 1) {		timerlat_top_main(argc, argv);		exit(0);	} 	if ((strcmp(argv[1], "-h") == 0) || (strcmp(argv[1], "--help") == 0)) {		timerlat_usage(0);	} else if (strncmp(argv[1], "-", 1) == 0) {		/* the user skipped the tool, call the default one */		timerlat_top_main(argc, argv);		exit(0);	} else if (strcmp(argv[1], "top") == 0) {		timerlat_top_main(argc-1, &argv[1]);		exit(0);	} else if (strcmp(argv[1], "hist") == 0) {		timerlat_hist_main(argc-1, &argv[1]);		exit(0);	} usage:	timerlat_usage(1);	exit(1);}