Commit d790ead8 authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
Browse files

perf tracepoint: Don't scan all tracepoints to test if one exists 



In is_valid_tracepoint, rather than scanning
"/sys/kernel/tracing/events/*/*" skipping any path where
"/sys/kernel/tracing/events/*/*/id" doesn't exist, and then testing if
"*:*" matches the tracepoint name, just use the given tracepoint name
replace the ':' with '/' and see if the id file exists.

This turns a nested directory search into a single file available test.

Rather than return 1 for valid and 0 for invalid, return true and false.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240509153245.1990426-1-irogers@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent c9d49237

tools/perf/util/tracepoint.c

+22 −34
Original line number Diff line number Diff line
@@ -4,10 +4,12 @@ 
#include <errno.h>

#include <fcntl.h>

#include <stdio.h>

#include <stdlib.h>

#include <sys/param.h>

#include <unistd.h>



#include <api/fs/tracing_path.h>

#include "fncache.h"



int tp_event_has_id(const char *dir_path, struct dirent *evt_dir)

{
@@ -26,39 +28,25 @@ int tp_event_has_id(const char *dir_path, struct dirent *evt_dir) 
/*

 * Check whether event is in <debugfs_mount_point>/tracing/events

 */

int is_valid_tracepoint(const char *event_string)

bool is_valid_tracepoint(const char *event_string)

{

	DIR *sys_dir, *evt_dir;

	struct dirent *sys_dirent, *evt_dirent;

	char evt_path[MAXPATHLEN];

	char *dir_path;



	sys_dir = tracing_events__opendir();

	if (!sys_dir)

		return 0;



	for_each_subsystem(sys_dir, sys_dirent) {

		dir_path = get_events_file(sys_dirent->d_name);

		if (!dir_path)

			continue;

		evt_dir = opendir(dir_path);

		if (!evt_dir)

			goto next;



		for_each_event(dir_path, evt_dir, evt_dirent) {

			snprintf(evt_path, MAXPATHLEN, "%s:%s",

				 sys_dirent->d_name, evt_dirent->d_name);

			if (!strcmp(evt_path, event_string)) {

				closedir(evt_dir);

				put_events_file(dir_path);

				closedir(sys_dir);

				return 1;

			}

		}

		closedir(evt_dir);

next:

		put_events_file(dir_path);

	}

	closedir(sys_dir);

	return 0;

	char *dst, *path = malloc(strlen(event_string) + 4); /* Space for "/id\0". */

	bool have_file = false; /* Conservatively return false if memory allocation failed. */

	const char *src;



	if (!path)

		return false;



	/* Copy event_string replacing the ':' with '/'. */

	for (src = event_string, dst = path; *src; src++, dst++)

		*dst = (*src == ':') ? '/' : *src;

	/* Add "/id\0". */

	memcpy(dst, "/id", 4);



	dst = get_events_file(path);

	if (dst)

		have_file = file_available(dst);

	free(dst);

	free(path);

	return have_file;

}

tools/perf/util/tracepoint.h

+2 −1
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 


#include <dirent.h>

#include <string.h>

#include <stdbool.h>



int tp_event_has_id(const char *dir_path, struct dirent *evt_dir);
@@ -20,6 +21,6 @@ int tp_event_has_id(const char *dir_path, struct dirent *evt_dir); 
		    (strcmp(sys_dirent->d_name, ".")) &&	\

		    (strcmp(sys_dirent->d_name, "..")))



int is_valid_tracepoint(const char *event_string);

bool is_valid_tracepoint(const char *event_string);



#endif /* __PERF_TRACEPOINT_H */