From 6b58e7f146f8d79c08f62087f928e1f01747de71 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Fri, 4 Sep 2009 16:39:51 -0300 Subject: [PATCH] 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 Signed-off-by: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Peter Zijlstra Cc: Mike Galbraith LKML-Reference: <20090904193951.GB6186@ghostprotocols.net> Signed-off-by: Ingo Molnar --- tools/perf/util/parse-events.c | 68 ++++++++++++++++++---------------- 1 file changed, 37 insertions(+), 31 deletions(-) diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index 89d46c99bc9c..52219d5a507b 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -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; - - 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, + sys_dir_fd = dirfd(sys_dir); + + 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; - - 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) { + sys_dir_fd = dirfd(sys_dir); + + 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, -- GitLab