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perf tools: Avoid unnecessary work in directory lookups 

This patch improves some (common) inefficiencies in the
handling of directory lookups:

- not using the d_type information returned by the kernel

- constructing (absolute) paths for file operation even though
  directory-relative operations using the *at functions is
  possible

There are more places to fix but this is a start.

Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20090904193951.GB6186@ghostprotocols.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
wifi-calibration
Ulrich Drepper 2009-09-04 16:39:51 -03:00 committed by Ingo Molnar
parent 849abde92b
commit 6b58e7f146
1 changed files with 35 additions and 29 deletions
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64
tools/perf/util/parse-events.c
View File

@ -1,14 +1,12 @@
#include "../perf.h"
#include "util.h"
#include "../perf.h"
#include "parse-options.h"
#include "parse-events.h"
#include "exec_cmd.h"
#include "string.h"
#include "cache.h"
extern char *strcasestr(const char *haystack, const char *needle);
int nr_counters;
struct perf_counter_attr attrs[MAX_COUNTERS];
@ -113,11 +111,9 @@ static unsigned long hw_cache_stat[C(MAX)] = {
[C(BPU)] = (CACHE_READ),
};
#define for_each_subsystem(sys_dir, sys_dirent, sys_next, file, st) \
#define for_each_subsystem(sys_dir, sys_dirent, sys_next) \
while (!readdir_r(sys_dir, &sys_dirent, &sys_next) && sys_next) \
if (snprintf(file, MAXPATHLEN, "%s/%s", debugfs_path, \
sys_dirent.d_name) && \
(!stat(file, &st)) && (S_ISDIR(st.st_mode)) && \
if (sys_dirent.d_type == DT_DIR && \
(strcmp(sys_dirent.d_name, ".")) && \
(strcmp(sys_dirent.d_name, "..")))
@ -136,11 +132,9 @@ static int tp_event_has_id(struct dirent *sys_dir, struct dirent *evt_dir)
return 0;
}
#define for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next, file, st) \
#define for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next) \
while (!readdir_r(evt_dir, &evt_dirent, &evt_next) && evt_next) \
if (snprintf(file, MAXPATHLEN, "%s/%s/%s", debugfs_path, \
sys_dirent.d_name, evt_dirent.d_name) && \
(!stat(file, &st)) && (S_ISDIR(st.st_mode)) && \
if (evt_dirent.d_type == DT_DIR && \
(strcmp(evt_dirent.d_name, ".")) && \
(strcmp(evt_dirent.d_name, "..")) && \
(!tp_event_has_id(&sys_dirent, &evt_dirent)))
@ -163,9 +157,8 @@ struct tracepoint_path *tracepoint_id_to_path(u64 config)
struct tracepoint_path *path = NULL;
DIR *sys_dir, *evt_dir;
struct dirent *sys_next, *evt_next, sys_dirent, evt_dirent;
struct stat st;
char id_buf[4];
int fd;
int sys_dir_fd, fd;
u64 id;
char evt_path[MAXPATHLEN];
@ -175,17 +168,23 @@ struct tracepoint_path *tracepoint_id_to_path(u64 config)
sys_dir = opendir(debugfs_path);
if (!sys_dir)
goto cleanup;
sys_dir_fd = dirfd(sys_dir);
for_each_subsystem(sys_dir, sys_dirent, sys_next, evt_path, st) {
evt_dir = opendir(evt_path);
if (!evt_dir)
goto cleanup;
for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next,
evt_path, st) {
snprintf(evt_path, MAXPATHLEN, "%s/%s/%s/id",
debugfs_path, sys_dirent.d_name,
for_each_subsystem(sys_dir, sys_dirent, sys_next) {
int dfd = openat(sys_dir_fd, sys_dirent.d_name,
O_RDONLY|O_DIRECTORY), evt_dir_fd;
if (dfd == -1)
continue;
evt_dir = fdopendir(dfd);
if (!evt_dir) {
close(dfd);
continue;
}
evt_dir_fd = dirfd(evt_dir);
for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next) {
snprintf(evt_path, MAXPATHLEN, "%s/id",
evt_dirent.d_name);
fd = open(evt_path, O_RDONLY);
fd = openat(evt_dir_fd, evt_path, O_RDONLY);
if (fd < 0)
continue;
if (read(fd, id_buf, sizeof(id_buf)) < 0) {
@ -629,7 +628,7 @@ static void print_tracepoint_events(void)
{
DIR *sys_dir, *evt_dir;
struct dirent *sys_next, *evt_next, sys_dirent, evt_dirent;
struct stat st;
int sys_dir_fd;
char evt_path[MAXPATHLEN];
if (valid_debugfs_mount(debugfs_path))
@ -638,13 +637,20 @@ static void print_tracepoint_events(void)
sys_dir = opendir(debugfs_path);
if (!sys_dir)
goto cleanup;
sys_dir_fd = dirfd(sys_dir);
for_each_subsystem(sys_dir, sys_dirent, sys_next, evt_path, st) {
evt_dir = opendir(evt_path);
if (!evt_dir)
goto cleanup;
for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next,
evt_path, st) {
for_each_subsystem(sys_dir, sys_dirent, sys_next) {
int dfd = openat(sys_dir_fd, sys_dirent.d_name,
O_RDONLY|O_DIRECTORY), evt_dir_fd;
if (dfd == -1)
continue;
evt_dir = fdopendir(dfd);
if (!evt_dir) {
close(dfd);
continue;
}
evt_dir_fd = dirfd(evt_dir);
for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next) {
snprintf(evt_path, MAXPATHLEN, "%s:%s",
sys_dirent.d_name, evt_dirent.d_name);
fprintf(stderr, " %-40s [%s]\n", evt_path,