Commit ebf294bf authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

perf tools: Simplify debugfs mountpoint handling code 

We don't need to have two PATH_MAX char sized arrays holding it, just
one in util/debugfs.c will do.

Also rename debugfs_path to tracing_events_path, as it is not the path
to debugfs, that is debugfs_mountpoint. Both are now accessible.

This will allow accessing this code in the perf python binding without
having to drag in perf.c and util/parse-events.c.

The defaults for these variables are the canonical "/sys/kernel/debug"
and "/sys/kernel/debug/tracing/events/", removing the need for simple
tools to call debugfs_mount(NULL).

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ug9jvtjrsqbluuhqqxpvg30f@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent c168fbfb

tools/perf/builtin-test.c

+2 −1
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 


#include "util/cache.h"

#include "util/debug.h"

#include "util/debugfs.h"

#include "util/evlist.h"

#include "util/parse-options.h"

#include "util/parse-events.h"
@@ -247,7 +248,7 @@ static int trace_event__id(const char *evname) 


	if (asprintf(&filename,

		     "%s/syscalls/%s/id",

		     debugfs_path, evname) < 0)

		     tracing_events_path, evname) < 0)

		return -1;



	fd = open(filename, O_RDONLY);

tools/perf/perf.c

+4 −29
Original line number Diff line number Diff line
@@ -29,8 +29,6 @@ struct pager_config { 
	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;
@@ -81,15 +79,6 @@ static void commit_pager_choice(void) 
	}

}



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;
@@ -161,15 +150,14 @@ static int handle_options(const char ***argv, int *argc, int *envchanged) 
				fprintf(stderr, "No directory given for --debugfs-dir.\n");

				usage(perf_usage_string);

			}

			strncpy(debugfs_mntpt, (*argv)[1], MAXPATHLEN);

			debugfs_mntpt[MAXPATHLEN - 1] = '\0';

			debugfs_set_path((*argv)[1]);

			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';

			debugfs_set_path(cmd + strlen(CMD_DEBUGFS_DIR));

			fprintf(stderr, "dir: %s\n", debugfs_mountpoint);

			if (envchanged)

				*envchanged = 1;

		} else {
@@ -281,7 +269,6 @@ static int run_builtin(struct cmd_struct *p, int argc, const char **argv) 
	if (use_pager == -1 && p->option & USE_PAGER)

		use_pager = 1;

	commit_pager_choice();

	set_debugfs_path();



	status = p->fn(argc, argv, prefix);

	exit_browser(status);
@@ -416,17 +403,6 @@ static int run_argv(int *argcp, const char ***argv) 
	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';

}



static void pthread__block_sigwinch(void)

{

	sigset_t set;
@@ -453,7 +429,7 @@ int main(int argc, const char **argv) 
	if (!cmd)

		cmd = "perf-help";

	/* get debugfs mount point from /proc/mounts */

	get_debugfs_mntpt();

	debugfs_mount(NULL);

	/*

	 * "perf-xxxx" is the same as "perf xxxx", but we obviously:

	 *
@@ -476,7 +452,6 @@ int main(int argc, const char **argv) 
	argc--;

	handle_options(&argv, &argc, NULL);

	commit_pager_choice();

	set_debugfs_path();

	set_buildid_dir();



	if (argc > 0) {

tools/perf/util/debugfs.c

+20 −5
Original line number Diff line number Diff line
@@ -2,10 +2,12 @@ 
#include "debugfs.h"

#include "cache.h"



#include <linux/kernel.h>

#include <sys/mount.h>



static int debugfs_premounted;

static char debugfs_mountpoint[PATH_MAX + 1];

char debugfs_mountpoint[PATH_MAX + 1] = "/sys/kernel/debug";

char tracing_events_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing/events";



static const char *debugfs_known_mountpoints[] = {

	"/sys/kernel/debug/",
@@ -64,7 +66,7 @@ const char *debugfs_find_mountpoint(void) 
	/* give up and parse /proc/mounts */

	fp = fopen("/proc/mounts", "r");

	if (fp == NULL)

		die("Can't open /proc/mounts for read");

		return NULL;



	while (fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",

		      debugfs_mountpoint, type) == 2) {
@@ -106,6 +108,12 @@ int debugfs_valid_entry(const char *path) 
	return 0;

}



static void debugfs_set_tracing_events_path(const char *mountpoint)

{

	snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s",

		 mountpoint, "tracing/events");

}



/* mount the debugfs somewhere if it's not mounted */



char *debugfs_mount(const char *mountpoint)
@@ -113,7 +121,7 @@ char *debugfs_mount(const char *mountpoint) 
	/* see if it's already mounted */

	if (debugfs_find_mountpoint()) {

		debugfs_premounted = 1;

		return debugfs_mountpoint;

		goto out;

	}



	/* if not mounted and no argument */
@@ -129,12 +137,19 @@ char *debugfs_mount(const char *mountpoint) 
		return NULL;



	/* save the mountpoint */

	strncpy(debugfs_mountpoint, mountpoint, sizeof(debugfs_mountpoint));

	debugfs_found = 1;



	strncpy(debugfs_mountpoint, mountpoint, sizeof(debugfs_mountpoint));

out:

	debugfs_set_tracing_events_path(debugfs_mountpoint);

	return debugfs_mountpoint;

}



void debugfs_set_path(const char *mountpoint)

{

	snprintf(debugfs_mountpoint, sizeof(debugfs_mountpoint), "%s", mountpoint);

	debugfs_set_tracing_events_path(mountpoint);

}



/* umount the debugfs */



int debugfs_umount(void)

tools/perf/util/debugfs.h

+4 −0
Original line number Diff line number Diff line
@@ -6,9 +6,13 @@ int debugfs_valid_mountpoint(const char *debugfs); 
int debugfs_valid_entry(const char *path);

char *debugfs_mount(const char *mountpoint);

int debugfs_umount(void);

void debugfs_set_path(const char *mountpoint);

int debugfs_write(const char *entry, const char *value);

int debugfs_read(const char *entry, char *buffer, size_t size);

void debugfs_force_cleanup(void);

int debugfs_make_path(const char *element, char *buffer, int size);



extern char debugfs_mountpoint[];

extern char tracing_events_path[];



#endif /* __DEBUGFS_H__ */

tools/perf/util/parse-events.c

+13 −15
Original line number Diff line number Diff line
@@ -25,8 +25,6 @@ enum event_result { 
	EVT_HANDLED_ALL

};



char debugfs_path[MAXPATHLEN];



#define CHW(x) .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_##x

#define CSW(x) .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_##x
@@ -140,7 +138,7 @@ static int tp_event_has_id(struct dirent *sys_dir, struct dirent *evt_dir) 
	char evt_path[MAXPATHLEN];

	int fd;



	snprintf(evt_path, MAXPATHLEN, "%s/%s/%s/id", debugfs_path,

	snprintf(evt_path, MAXPATHLEN, "%s/%s/%s/id", tracing_events_path,

			sys_dir->d_name, evt_dir->d_name);

	fd = open(evt_path, O_RDONLY);

	if (fd < 0)
@@ -171,16 +169,16 @@ struct tracepoint_path *tracepoint_id_to_path(u64 config) 
	char evt_path[MAXPATHLEN];

	char dir_path[MAXPATHLEN];



	if (debugfs_valid_mountpoint(debugfs_path))

	if (debugfs_valid_mountpoint(tracing_events_path))

		return NULL;



	sys_dir = opendir(debugfs_path);

	sys_dir = opendir(tracing_events_path);

	if (!sys_dir)

		return NULL;



	for_each_subsystem(sys_dir, sys_dirent, sys_next) {



		snprintf(dir_path, MAXPATHLEN, "%s/%s", debugfs_path,

		snprintf(dir_path, MAXPATHLEN, "%s/%s", tracing_events_path,

			 sys_dirent.d_name);

		evt_dir = opendir(dir_path);

		if (!evt_dir)
@@ -447,7 +445,7 @@ parse_single_tracepoint_event(char *sys_name, 
	u64 id;

	int fd;



	snprintf(evt_path, MAXPATHLEN, "%s/%s/%s/id", debugfs_path,

	snprintf(evt_path, MAXPATHLEN, "%s/%s/%s/id", tracing_events_path,

		 sys_name, evt_name);



	fd = open(evt_path, O_RDONLY);
@@ -485,7 +483,7 @@ parse_multiple_tracepoint_event(struct perf_evlist *evlist, char *sys_name, 
	struct dirent *evt_ent;

	DIR *evt_dir;



	snprintf(evt_path, MAXPATHLEN, "%s/%s", debugfs_path, sys_name);

	snprintf(evt_path, MAXPATHLEN, "%s/%s", tracing_events_path, sys_name);

	evt_dir = opendir(evt_path);



	if (!evt_dir) {
@@ -528,7 +526,7 @@ parse_tracepoint_event(struct perf_evlist *evlist, const char **strp, 
	char sys_name[MAX_EVENT_LENGTH];

	unsigned int sys_length, evt_length;



	if (debugfs_valid_mountpoint(debugfs_path))

	if (debugfs_valid_mountpoint(tracing_events_path))

		return 0;



	evt_name = strchr(*strp, ':');
@@ -920,10 +918,10 @@ void print_tracepoint_events(const char *subsys_glob, const char *event_glob) 
	char evt_path[MAXPATHLEN];

	char dir_path[MAXPATHLEN];



	if (debugfs_valid_mountpoint(debugfs_path))

	if (debugfs_valid_mountpoint(tracing_events_path))

		return;



	sys_dir = opendir(debugfs_path);

	sys_dir = opendir(tracing_events_path);

	if (!sys_dir)

		return;
@@ -932,7 +930,7 @@ void print_tracepoint_events(const char *subsys_glob, const char *event_glob) 
		    !strglobmatch(sys_dirent.d_name, subsys_glob))

			continue;



		snprintf(dir_path, MAXPATHLEN, "%s/%s", debugfs_path,

		snprintf(dir_path, MAXPATHLEN, "%s/%s", tracing_events_path,

			 sys_dirent.d_name);

		evt_dir = opendir(dir_path);

		if (!evt_dir)
@@ -964,16 +962,16 @@ int is_valid_tracepoint(const char *event_string) 
	char evt_path[MAXPATHLEN];

	char dir_path[MAXPATHLEN];



	if (debugfs_valid_mountpoint(debugfs_path))

	if (debugfs_valid_mountpoint(tracing_events_path))

		return 0;



	sys_dir = opendir(debugfs_path);

	sys_dir = opendir(tracing_events_path);

	if (!sys_dir)

		return 0;



	for_each_subsystem(sys_dir, sys_dirent, sys_next) {



		snprintf(dir_path, MAXPATHLEN, "%s/%s", debugfs_path,

		snprintf(dir_path, MAXPATHLEN, "%s/%s", tracing_events_path,

			 sys_dirent.d_name);

		evt_dir = opendir(dir_path);

		if (!evt_dir)

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