tools/perf/perf.c - kernel/msm-5.4 - Gitiles

 /*
  * perf.c
  *
  * Performance analysis utility.
  *
  * This is the main hub from which the sub-commands (perf stat,
  * perf top, perf record, perf report, etc.) are started.
  */
 #include "builtin.h"

 #include "util/exec_cmd.h"
 #include "util/cache.h"
 #include "util/quote.h"
 #include "util/run-command.h"
 #include "util/parse-events.h"
 #include "util/string.h"
 #include "util/debugfs.h"

 const char perf_usage_string[] =
 	"perf [--version] [--help] COMMAND [ARGS]";

 const char perf_more_info_string[] =
 	"See 'perf help COMMAND' for more information on a specific command.";

 static int use_pager = -1;
 struct pager_config {
 	const char *cmd;
 	int val;
 };

 static char debugfs_mntpt[MAXPATHLEN];

 static int pager_command_config(const char *var, const char *value, void *data)
 {
 	struct pager_config *c = data;
 	if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
 		c->val = perf_config_bool(var, value);
 	return 0;
 }

 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
 int check_pager_config(const char *cmd)
 {
 	struct pager_config c;
 	c.cmd = cmd;
 	c.val = -1;
 	perf_config(pager_command_config, &c);
 	return c.val;
 }

 static void commit_pager_choice(void) {
 	switch (use_pager) {
 	case 0:
 		setenv("PERF_PAGER", "cat", 1);
 		break;
 	case 1:
 		/* setup_pager(); */
 		break;
 	default:
 		break;
 	}
 }

 static void set_debugfs_path(void)
 {
 	char *path;

 	path = getenv(PERF_DEBUGFS_ENVIRONMENT);
 	snprintf(debugfs_path, MAXPATHLEN, "%s/%s", path ?: debugfs_mntpt,
 		 "tracing/events");
 }

 static int handle_options(const char*** argv, int* argc, int* envchanged)
 {
 	int handled = 0;

 	while (*argc > 0) {
 		const char *cmd = (*argv)[0];
 		if (cmd[0] != '-')
 			break;

 		/*
 		 * For legacy reasons, the "version" and "help"
 		 * commands can be written with "--" prepended
 		 * to make them look like flags.
 		 */
 		if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
 			break;

 		/*
 		 * Check remaining flags.
 		 */
 		if (!prefixcmp(cmd, CMD_EXEC_PATH)) {
 			cmd += strlen(CMD_EXEC_PATH);
 			if (*cmd == '=')
 				perf_set_argv_exec_path(cmd + 1);
 			else {
 				puts(perf_exec_path());
 				exit(0);
 			}
 		} else if (!strcmp(cmd, "--html-path")) {
 			puts(system_path(PERF_HTML_PATH));
 			exit(0);
 		} else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 			use_pager = 1;
 		} else if (!strcmp(cmd, "--no-pager")) {
 			use_pager = 0;
 			if (envchanged)
 				*envchanged = 1;
 		} else if (!strcmp(cmd, "--perf-dir")) {
 			if (*argc < 2) {
 				fprintf(stderr, "No directory given for --perf-dir.\n" );
 				usage(perf_usage_string);
 			}
 			setenv(PERF_DIR_ENVIRONMENT, (*argv)[1], 1);
 			if (envchanged)
 				*envchanged = 1;
 			(*argv)++;
 			(*argc)--;
 			handled++;
 		} else if (!prefixcmp(cmd, CMD_PERF_DIR)) {
 			setenv(PERF_DIR_ENVIRONMENT, cmd + strlen(CMD_PERF_DIR), 1);
 			if (envchanged)
 				*envchanged = 1;
 		} else if (!strcmp(cmd, "--work-tree")) {
 			if (*argc < 2) {
 				fprintf(stderr, "No directory given for --work-tree.\n" );
 				usage(perf_usage_string);
 			}
 			setenv(PERF_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 			if (envchanged)
 				*envchanged = 1;
 			(*argv)++;
 			(*argc)--;
 		} else if (!prefixcmp(cmd, CMD_WORK_TREE)) {
 			setenv(PERF_WORK_TREE_ENVIRONMENT, cmd + strlen(CMD_WORK_TREE), 1);
 			if (envchanged)
 				*envchanged = 1;
 		} else if (!strcmp(cmd, "--debugfs-dir")) {
 			if (*argc < 2) {
 				fprintf(stderr, "No directory given for --debugfs-dir.\n");
 				usage(perf_usage_string);
 			}
 			strncpy(debugfs_mntpt, (*argv)[1], MAXPATHLEN);
 			debugfs_mntpt[MAXPATHLEN - 1] = '\0';
 			if (envchanged)
 				*envchanged = 1;
 			(*argv)++;
 			(*argc)--;
 		} else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
 			strncpy(debugfs_mntpt, cmd + strlen(CMD_DEBUGFS_DIR), MAXPATHLEN);
 			debugfs_mntpt[MAXPATHLEN - 1] = '\0';
 			if (envchanged)
 				*envchanged = 1;
 		} else {
 			fprintf(stderr, "Unknown option: %s\n", cmd);
 			usage(perf_usage_string);
 		}

 		(*argv)++;
 		(*argc)--;
 		handled++;
 	}
 	return handled;
 }

 static int handle_alias(int *argcp, const char ***argv)
 {
 	int envchanged = 0, ret = 0, saved_errno = errno;
 	int count, option_count;
 	const char** new_argv;
 	const char *alias_command;
 	char *alias_string;

 	alias_command = (*argv)[0];
 	alias_string = alias_lookup(alias_command);
 	if (alias_string) {
 		if (alias_string[0] == '!') {
 			if (*argcp > 1) {
 				struct strbuf buf;

 				strbuf_init(&buf, PATH_MAX);
 				strbuf_addstr(&buf, alias_string);
 				sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
 				free(alias_string);
 				alias_string = buf.buf;
 			}
 			ret = system(alias_string + 1);
 			if (ret >= 0 && WIFEXITED(ret) &&
 			    WEXITSTATUS(ret) != 127)
 				exit(WEXITSTATUS(ret));
 			die("Failed to run '%s' when expanding alias '%s'",
 			    alias_string + 1, alias_command);
 		}
 		count = split_cmdline(alias_string, &new_argv);
 		if (count < 0)
 			die("Bad alias.%s string", alias_command);
 		option_count = handle_options(&new_argv, &count, &envchanged);
 		if (envchanged)
 			die("alias '%s' changes environment variables\n"
 				 "You can use '!perf' in the alias to do this.",
 				 alias_command);
 		memmove(new_argv - option_count, new_argv,
 				count * sizeof(char *));
 		new_argv -= option_count;

 		if (count < 1)
 			die("empty alias for %s", alias_command);

 		if (!strcmp(alias_command, new_argv[0]))
 			die("recursive alias: %s", alias_command);

 		new_argv = realloc(new_argv, sizeof(char*) *
 				    (count + *argcp + 1));
 		/* insert after command name */
 		memcpy(new_argv + count, *argv + 1, sizeof(char*) * *argcp);
 		new_argv[count+*argcp] = NULL;

 		*argv = new_argv;
 		*argcp += count - 1;

 		ret = 1;
 	}

 	errno = saved_errno;

 	return ret;
 }

 const char perf_version_string[] = PERF_VERSION;

 #define RUN_SETUP	(1<<0)
 #define USE_PAGER	(1<<1)
 /*
  * require working tree to be present -- anything uses this needs
  * RUN_SETUP for reading from the configuration file.
  */
 #define NEED_WORK_TREE	(1<<2)

 struct cmd_struct {
 	const char *cmd;
 	int (*fn)(int, const char **, const char *);
 	int option;
 };

 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 {
 	int status;
 	struct stat st;
 	const char *prefix;

 	prefix = NULL;
 	if (p->option & RUN_SETUP)
 		prefix = NULL; /* setup_perf_directory(); */

 	if (use_pager == -1 && p->option & RUN_SETUP)
 		use_pager = check_pager_config(p->cmd);
 	if (use_pager == -1 && p->option & USE_PAGER)
 		use_pager = 1;
 	commit_pager_choice();
 	set_debugfs_path();

 	status = p->fn(argc, argv, prefix);
 	if (status)
 		return status & 0xff;

 	/* Somebody closed stdout? */
 	if (fstat(fileno(stdout), &st))
 		return 0;
 	/* Ignore write errors for pipes and sockets.. */
 	if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 		return 0;

 	/* Check for ENOSPC and EIO errors.. */
 	if (fflush(stdout))
 		die("write failure on standard output: %s", strerror(errno));
 	if (ferror(stdout))
 		die("unknown write failure on standard output");
 	if (fclose(stdout))
 		die("close failed on standard output: %s", strerror(errno));
 	return 0;
 }

 static void handle_internal_command(int argc, const char **argv)
 {
 	const char *cmd = argv[0];
 	static struct cmd_struct commands[] = {
 		{ "buildid-cache", cmd_buildid_cache, 0 },
 		{ "buildid-list", cmd_buildid_list, 0 },
 		{ "diff",	cmd_diff,	0 },
 		{ "help",	cmd_help,	0 },
 		{ "list",	cmd_list,	0 },
 		{ "record",	cmd_record,	0 },
 		{ "report",	cmd_report,	0 },
 		{ "bench",	cmd_bench,	0 },
 		{ "stat",	cmd_stat,	0 },
 		{ "timechart",	cmd_timechart,	0 },
 		{ "top",	cmd_top,	0 },
 		{ "annotate",	cmd_annotate,	0 },
 		{ "version",	cmd_version,	0 },
 		{ "trace",	cmd_trace,	0 },
 		{ "sched",	cmd_sched,	0 },
 		{ "probe",	cmd_probe,	0 },
 		{ "kmem",	cmd_kmem,	0 },
 	};
 	unsigned int i;
 	static const char ext[] = STRIP_EXTENSION;

 	if (sizeof(ext) > 1) {
 		i = strlen(argv[0]) - strlen(ext);
 		if (i > 0 && !strcmp(argv[0] + i, ext)) {
 			char *argv0 = strdup(argv[0]);
 			argv[0] = cmd = argv0;
 			argv0[i] = '\0';
 		}
 	}

 	/* Turn "perf cmd --help" into "perf help cmd" */
 	if (argc > 1 && !strcmp(argv[1], "--help")) {
 		argv[1] = argv[0];
 		argv[0] = cmd = "help";
 	}

 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
 		struct cmd_struct *p = commands+i;
 		if (strcmp(p->cmd, cmd))
 			continue;
 		exit(run_builtin(p, argc, argv));
 	}
 }

 static void execv_dashed_external(const char **argv)
 {
 	struct strbuf cmd = STRBUF_INIT;
 	const char *tmp;
 	int status;

 	strbuf_addf(&cmd, "perf-%s", argv[0]);

 	/*
 	 * argv[0] must be the perf command, but the argv array
 	 * belongs to the caller, and may be reused in
 	 * subsequent loop iterations. Save argv[0] and
 	 * restore it on error.
 	 */
 	tmp = argv[0];
 	argv[0] = cmd.buf;

 	/*
 	 * if we fail because the command is not found, it is
 	 * OK to return. Otherwise, we just pass along the status code.
 	 */
 	status = run_command_v_opt(argv, 0);
 	if (status != -ERR_RUN_COMMAND_EXEC) {
 		if (IS_RUN_COMMAND_ERR(status))
 			die("unable to run '%s'", argv[0]);
 		exit(-status);
 	}
 	errno = ENOENT; /* as if we called execvp */

 	argv[0] = tmp;

 	strbuf_release(&cmd);
 }

 static int run_argv(int *argcp, const char ***argv)
 {
 	int done_alias = 0;

 	while (1) {
 		/* See if it's an internal command */
 		handle_internal_command(*argcp, *argv);

 		/* .. then try the external ones */
 		execv_dashed_external(*argv);

 		/* It could be an alias -- this works around the insanity
 		 * of overriding "perf log" with "perf show" by having
 		 * alias.log = show
 		 */
 		if (done_alias || !handle_alias(argcp, argv))
 			break;
 		done_alias = 1;
 	}

 	return done_alias;
 }

 /* mini /proc/mounts parser: searching for "^blah /mount/point debugfs" */
 static void get_debugfs_mntpt(void)
 {
 	const char *path = debugfs_mount(NULL);

 	if (path)
 		strncpy(debugfs_mntpt, path, sizeof(debugfs_mntpt));
 	else
 		debugfs_mntpt[0] = '\0';
 }

 int main(int argc, const char **argv)
 {
 	const char *cmd;

 	cmd = perf_extract_argv0_path(argv[0]);
 	if (!cmd)
 		cmd = "perf-help";
 	/* get debugfs mount point from /proc/mounts */
 	get_debugfs_mntpt();
 	/*
 	 * "perf-xxxx" is the same as "perf xxxx", but we obviously:
 	 *
 	 *  - cannot take flags in between the "perf" and the "xxxx".
 	 *  - cannot execute it externally (since it would just do
 	 *    the same thing over again)
 	 *
 	 * So we just directly call the internal command handler, and
 	 * die if that one cannot handle it.
 	 */
 	if (!prefixcmp(cmd, "perf-")) {
 		cmd += 5;
 		argv[0] = cmd;
 		handle_internal_command(argc, argv);
 		die("cannot handle %s internally", cmd);
 	}

 	/* Look for flags.. */
 	argv++;
 	argc--;
 	handle_options(&argv, &argc, NULL);
 	commit_pager_choice();
 	set_debugfs_path();
 	if (argc > 0) {
 		if (!prefixcmp(argv[0], "--"))
 			argv[0] += 2;
 	} else {
 		/* The user didn't specify a command; give them help */
 		printf("\n usage: %s\n\n", perf_usage_string);
 		list_common_cmds_help();
 		printf("\n %s\n\n", perf_more_info_string);
 		exit(1);
 	}
 	cmd = argv[0];

 	/*
 	 * We use PATH to find perf commands, but we prepend some higher
 	 * precidence paths: the "--exec-path" option, the PERF_EXEC_PATH
 	 * environment, and the $(perfexecdir) from the Makefile at build
 	 * time.
 	 */
 	setup_path();

 	while (1) {
 		static int done_help = 0;
 		static int was_alias = 0;

 		was_alias = run_argv(&argc, &argv);
 		if (errno != ENOENT)
 			break;

 		if (was_alias) {
 			fprintf(stderr, "Expansion of alias '%s' failed; "
 				"'%s' is not a perf-command\n",
 				cmd, argv[0]);
 			exit(1);
 		}
 		if (!done_help) {
 			cmd = argv[0] = help_unknown_cmd(cmd);
 			done_help = 1;
 		} else
 			break;
 	}

 	fprintf(stderr, "Failed to run command '%s': %s\n",
 		cmd, strerror(errno));

 	return 1;
 }
	/*
	* perf.c
	*
	* Performance analysis utility.
	*
	* This is the main hub from which the sub-commands (perf stat,
	* perf top, perf record, perf report, etc.) are started.
	*/
	#include "builtin.h"

	#include "util/exec_cmd.h"
	#include "util/cache.h"
	#include "util/quote.h"
	#include "util/run-command.h"
	#include "util/parse-events.h"
	#include "util/string.h"
	#include "util/debugfs.h"

	const char perf_usage_string[] =
	"perf [--version] [--help] COMMAND [ARGS]";

	const char perf_more_info_string[] =
	"See 'perf help COMMAND' for more information on a specific command.";

	static int use_pager = -1;
	struct pager_config {
	const char *cmd;
	int val;
	};

	static char debugfs_mntpt[MAXPATHLEN];

	static int pager_command_config(const char var, const char value, void *data)
	{
	struct pager_config *c = data;
	if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
	c->val = perf_config_bool(var, value);
	return 0;
	}

	/* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
	int check_pager_config(const char *cmd)
	{
	struct pager_config c;
	c.cmd = cmd;
	c.val = -1;
	perf_config(pager_command_config, &c);
	return c.val;
	}

	static void commit_pager_choice(void) {
	switch (use_pager) {
	case 0:
	setenv("PERF_PAGER", "cat", 1);
	break;
	case 1:
	/* setup_pager(); */
	break;
	default:
	break;
	}
	}

	static void set_debugfs_path(void)
	{
	char *path;

	path = getenv(PERF_DEBUGFS_ENVIRONMENT);
	snprintf(debugfs_path, MAXPATHLEN, "%s/%s", path ?: debugfs_mntpt,
	"tracing/events");
	}

	static int handle_options(const char*** argv, int* argc, int* envchanged)
	{
	int handled = 0;

	while (*argc > 0) {
	const char cmd = (argv)[0];
	if (cmd[0] != '-')
	break;

	/*
	* For legacy reasons, the "version" and "help"
	* commands can be written with "--" prepended
	* to make them look like flags.
	*/
	if (!strcmp(cmd, "--help") \|\| !strcmp(cmd, "--version"))
	break;

	/*
	* Check remaining flags.
	*/
	if (!prefixcmp(cmd, CMD_EXEC_PATH)) {
	cmd += strlen(CMD_EXEC_PATH);
	if (*cmd == '=')
	perf_set_argv_exec_path(cmd + 1);
	else {
	puts(perf_exec_path());
	exit(0);
	}
	} else if (!strcmp(cmd, "--html-path")) {
	puts(system_path(PERF_HTML_PATH));
	exit(0);
	} else if (!strcmp(cmd, "-p") \|\| !strcmp(cmd, "--paginate")) {
	use_pager = 1;
	} else if (!strcmp(cmd, "--no-pager")) {
	use_pager = 0;
	if (envchanged)
	*envchanged = 1;
	} else if (!strcmp(cmd, "--perf-dir")) {
	if (*argc < 2) {
	fprintf(stderr, "No directory given for --perf-dir.\n" );
	usage(perf_usage_string);
	}
	setenv(PERF_DIR_ENVIRONMENT, (*argv)[1], 1);
	if (envchanged)
	*envchanged = 1;
	(*argv)++;
	(*argc)--;
	handled++;
	} else if (!prefixcmp(cmd, CMD_PERF_DIR)) {
	setenv(PERF_DIR_ENVIRONMENT, cmd + strlen(CMD_PERF_DIR), 1);
	if (envchanged)
	*envchanged = 1;
	} else if (!strcmp(cmd, "--work-tree")) {
	if (*argc < 2) {
	fprintf(stderr, "No directory given for --work-tree.\n" );
	usage(perf_usage_string);
	}
	setenv(PERF_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
	if (envchanged)
	*envchanged = 1;
	(*argv)++;
	(*argc)--;
	} else if (!prefixcmp(cmd, CMD_WORK_TREE)) {
	setenv(PERF_WORK_TREE_ENVIRONMENT, cmd + strlen(CMD_WORK_TREE), 1);
	if (envchanged)
	*envchanged = 1;
	} else if (!strcmp(cmd, "--debugfs-dir")) {
	if (*argc < 2) {
	fprintf(stderr, "No directory given for --debugfs-dir.\n");
	usage(perf_usage_string);
	}
	strncpy(debugfs_mntpt, (*argv)[1], MAXPATHLEN);
	debugfs_mntpt[MAXPATHLEN - 1] = '\0';
	if (envchanged)
	*envchanged = 1;
	(*argv)++;
	(*argc)--;
	} else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
	strncpy(debugfs_mntpt, cmd + strlen(CMD_DEBUGFS_DIR), MAXPATHLEN);
	debugfs_mntpt[MAXPATHLEN - 1] = '\0';
	if (envchanged)
	*envchanged = 1;
	} else {
	fprintf(stderr, "Unknown option: %s\n", cmd);
	usage(perf_usage_string);
	}

	(*argv)++;
	(*argc)--;
	handled++;
	}
	return handled;
	}

	static int handle_alias(int argcp, const char **argv)
	{
	int envchanged = 0, ret = 0, saved_errno = errno;
	int count, option_count;
	const char** new_argv;
	const char *alias_command;
	char *alias_string;

	alias_command = (*argv)[0];
	alias_string = alias_lookup(alias_command);
	if (alias_string) {
	if (alias_string[0] == '!') {
	if (*argcp > 1) {
	struct strbuf buf;

	strbuf_init(&buf, PATH_MAX);
	strbuf_addstr(&buf, alias_string);
	sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
	free(alias_string);
	alias_string = buf.buf;
	}
	ret = system(alias_string + 1);
	if (ret >= 0 && WIFEXITED(ret) &&
	WEXITSTATUS(ret) != 127)
	exit(WEXITSTATUS(ret));
	die("Failed to run '%s' when expanding alias '%s'",
	alias_string + 1, alias_command);
	}
	count = split_cmdline(alias_string, &new_argv);
	if (count < 0)
	die("Bad alias.%s string", alias_command);
	option_count = handle_options(&new_argv, &count, &envchanged);
	if (envchanged)
	die("alias '%s' changes environment variables\n"
	"You can use '!perf' in the alias to do this.",
	alias_command);
	memmove(new_argv - option_count, new_argv,
	count * sizeof(char *));
	new_argv -= option_count;

	if (count < 1)
	die("empty alias for %s", alias_command);

	if (!strcmp(alias_command, new_argv[0]))
	die("recursive alias: %s", alias_command);

	new_argv = realloc(new_argv, sizeof(char)
	(count + *argcp + 1));
	/* insert after command name */
	memcpy(new_argv + count, argv + 1, sizeof(char) * *argcp);
	new_argv[count+*argcp] = NULL;

	*argv = new_argv;
	*argcp += count - 1;

	ret = 1;
	}

	errno = saved_errno;

	return ret;
	}

	const char perf_version_string[] = PERF_VERSION;

	#define RUN_SETUP (1<<0)
	#define USE_PAGER (1<<1)
	/*
	* require working tree to be present -- anything uses this needs
	* RUN_SETUP for reading from the configuration file.
	*/
	#define NEED_WORK_TREE (1<<2)

	struct cmd_struct {
	const char *cmd;
	int (fn)(int, const char , const char );
	int option;
	};

	static int run_builtin(struct cmd_struct p, int argc, const char *argv)
	{
	int status;
	struct stat st;
	const char *prefix;

	prefix = NULL;
	if (p->option & RUN_SETUP)
	prefix = NULL; /* setup_perf_directory(); */

	if (use_pager == -1 && p->option & RUN_SETUP)
	use_pager = check_pager_config(p->cmd);
	if (use_pager == -1 && p->option & USE_PAGER)
	use_pager = 1;
	commit_pager_choice();
	set_debugfs_path();

	status = p->fn(argc, argv, prefix);
	if (status)
	return status & 0xff;

	/* Somebody closed stdout? */
	if (fstat(fileno(stdout), &st))
	return 0;
	/* Ignore write errors for pipes and sockets.. */
	if (S_ISFIFO(st.st_mode) \|\| S_ISSOCK(st.st_mode))
	return 0;

	/* Check for ENOSPC and EIO errors.. */
	if (fflush(stdout))
	die("write failure on standard output: %s", strerror(errno));
	if (ferror(stdout))
	die("unknown write failure on standard output");
	if (fclose(stdout))
	die("close failed on standard output: %s", strerror(errno));
	return 0;
	}

	static void handle_internal_command(int argc, const char **argv)
	{
	const char *cmd = argv[0];
	static struct cmd_struct commands[] = {
	{ "buildid-cache", cmd_buildid_cache, 0 },
	{ "buildid-list", cmd_buildid_list, 0 },
	{ "diff", cmd_diff, 0 },
	{ "help", cmd_help, 0 },
	{ "list", cmd_list, 0 },
	{ "record", cmd_record, 0 },
	{ "report", cmd_report, 0 },
	{ "bench", cmd_bench, 0 },
	{ "stat", cmd_stat, 0 },
	{ "timechart", cmd_timechart, 0 },
	{ "top", cmd_top, 0 },
	{ "annotate", cmd_annotate, 0 },
	{ "version", cmd_version, 0 },
	{ "trace", cmd_trace, 0 },
	{ "sched", cmd_sched, 0 },
	{ "probe", cmd_probe, 0 },
	{ "kmem", cmd_kmem, 0 },
	};
	unsigned int i;
	static const char ext[] = STRIP_EXTENSION;

	if (sizeof(ext) > 1) {
	i = strlen(argv[0]) - strlen(ext);
	if (i > 0 && !strcmp(argv[0] + i, ext)) {
	char *argv0 = strdup(argv[0]);
	argv[0] = cmd = argv0;
	argv0[i] = '\0';
	}
	}

	/* Turn "perf cmd --help" into "perf help cmd" */
	if (argc > 1 && !strcmp(argv[1], "--help")) {
	argv[1] = argv[0];
	argv[0] = cmd = "help";
	}

	for (i = 0; i < ARRAY_SIZE(commands); i++) {
	struct cmd_struct *p = commands+i;
	if (strcmp(p->cmd, cmd))
	continue;
	exit(run_builtin(p, argc, argv));
	}
	}

	static void execv_dashed_external(const char **argv)
	{
	struct strbuf cmd = STRBUF_INIT;
	const char *tmp;
	int status;

	strbuf_addf(&cmd, "perf-%s", argv[0]);

	/*
	* argv[0] must be the perf command, but the argv array
	* belongs to the caller, and may be reused in
	* subsequent loop iterations. Save argv[0] and
	* restore it on error.
	*/
	tmp = argv[0];
	argv[0] = cmd.buf;

	/*
	* if we fail because the command is not found, it is
	* OK to return. Otherwise, we just pass along the status code.
	*/
	status = run_command_v_opt(argv, 0);
	if (status != -ERR_RUN_COMMAND_EXEC) {
	if (IS_RUN_COMMAND_ERR(status))
	die("unable to run '%s'", argv[0]);
	exit(-status);
	}
	errno = ENOENT; /* as if we called execvp */

	argv[0] = tmp;

	strbuf_release(&cmd);
	}

	static int run_argv(int argcp, const char **argv)
	{
	int done_alias = 0;

	while (1) {
	/* See if it's an internal command */
	handle_internal_command(argcp, argv);

	/* .. then try the external ones */
	execv_dashed_external(*argv);

	/* It could be an alias -- this works around the insanity
	* of overriding "perf log" with "perf show" by having
	* alias.log = show
	*/
	if (done_alias \|\| !handle_alias(argcp, argv))
	break;
	done_alias = 1;
	}

	return done_alias;
	}

	/* mini /proc/mounts parser: searching for "^blah /mount/point debugfs" */
	static void get_debugfs_mntpt(void)
	{
	const char *path = debugfs_mount(NULL);

	if (path)
	strncpy(debugfs_mntpt, path, sizeof(debugfs_mntpt));
	else
	debugfs_mntpt[0] = '\0';
	}

	int main(int argc, const char **argv)
	{
	const char *cmd;

	cmd = perf_extract_argv0_path(argv[0]);
	if (!cmd)
	cmd = "perf-help";
	/* get debugfs mount point from /proc/mounts */
	get_debugfs_mntpt();
	/*
	* "perf-xxxx" is the same as "perf xxxx", but we obviously:
	*
	* - cannot take flags in between the "perf" and the "xxxx".
	* - cannot execute it externally (since it would just do
	* the same thing over again)
	*
	* So we just directly call the internal command handler, and
	* die if that one cannot handle it.
	*/
	if (!prefixcmp(cmd, "perf-")) {
	cmd += 5;
	argv[0] = cmd;
	handle_internal_command(argc, argv);
	die("cannot handle %s internally", cmd);
	}

	/* Look for flags.. */
	argv++;
	argc--;
	handle_options(&argv, &argc, NULL);
	commit_pager_choice();
	set_debugfs_path();
	if (argc > 0) {
	if (!prefixcmp(argv[0], "--"))
	argv[0] += 2;
	} else {
	/* The user didn't specify a command; give them help */
	printf("\n usage: %s\n\n", perf_usage_string);
	list_common_cmds_help();
	printf("\n %s\n\n", perf_more_info_string);
	exit(1);
	}
	cmd = argv[0];

	/*
	* We use PATH to find perf commands, but we prepend some higher
	* precidence paths: the "--exec-path" option, the PERF_EXEC_PATH
	* environment, and the $(perfexecdir) from the Makefile at build
	* time.
	*/
	setup_path();

	while (1) {
	static int done_help = 0;
	static int was_alias = 0;

	was_alias = run_argv(&argc, &argv);
	if (errno != ENOENT)
	break;

	if (was_alias) {
	fprintf(stderr, "Expansion of alias '%s' failed; "
	"'%s' is not a perf-command\n",
	cmd, argv[0]);
	exit(1);
	}
	if (!done_help) {
	cmd = argv[0] = help_unknown_cmd(cmd);
	done_help = 1;
	} else
	break;
	}

	fprintf(stderr, "Failed to run command '%s': %s\n",
	cmd, strerror(errno));

	return 1;
	}