perf tools: Do a few more directory handling optimizations
Ulrich Drepper [Sat, 19 Dec 2009 21:40:28 +0000 (16:40 -0500)]
A few more optimizations for perf when dealing with directories.

Some of them significantly cut down the work which has to be
done. d_type should always be set; otherwise fix the kernel
code. And there are functions available to parse fstab-like
files, so use them.

Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: a.p.zijlstra@chello.nl
Cc: acme@redhat.com
Cc: eranian@google.com
Cc: fweisbec@gmail.com
Cc: lizf@cn.fujitsu.com
Cc: paulus@samba.org
Cc: xiaoguangrong@cn.fujitsu.com
LKML-Reference: <200912192140.nBJLeSfA028905@hs20-bc2-1.build.redhat.com>
[ v2: two small stylistic fixlets ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/builtin-kmem.c
tools/perf/util/trace-event-info.c

index 4c06828..05dc5a7 100644 (file)
@@ -92,23 +92,18 @@ static void setup_cpunode_map(void)
        if (!dir1)
                return;
 
-       while (true) {
-               dent1 = readdir(dir1);
-               if (!dent1)
-                       break;
-
-               if (sscanf(dent1->d_name, "node%u", &mem) < 1)
+       while ((dent1 = readdir(dir1)) != NULL) {
+               if (dent1->d_type != DT_DIR ||
+                   sscanf(dent1->d_name, "node%u", &mem) < 1)
                        continue;
 
                snprintf(buf, PATH_MAX, "%s/%s", PATH_SYS_NODE, dent1->d_name);
                dir2 = opendir(buf);
                if (!dir2)
                        continue;
-               while (true) {
-                       dent2 = readdir(dir2);
-                       if (!dent2)
-                               break;
-                       if (sscanf(dent2->d_name, "cpu%u", &cpu) < 1)
+               while ((dent2 = readdir(dir2)) != NULL) {
+                       if (dent2->d_type != DT_LNK ||
+                           sscanf(dent2->d_name, "cpu%u", &cpu) < 1)
                                continue;
                        cpunode_map[cpu] = mem;
                }
index cace355..dfef238 100644 (file)
@@ -20,6 +20,7 @@
  */
 #define _GNU_SOURCE
 #include <dirent.h>
+#include <mntent.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -103,28 +104,28 @@ static const char *find_debugfs(void)
 {
        static char debugfs[MAX_PATH+1];
        static int debugfs_found;
-       char type[100];
        FILE *fp;
+       struct mntent *m;
 
        if (debugfs_found)
                return debugfs;
 
-       if ((fp = fopen("/proc/mounts","r")) == NULL)
+       fp = setmntent("/proc/mounts", "r");
+       if (!fp)
                die("Can't open /proc/mounts for read");
 
-       while (fscanf(fp, "%*s %"
-                     STR(MAX_PATH)
-                     "s %99s %*s %*d %*d\n",
-                     debugfs, type) == 2) {
-               if (strcmp(type, "debugfs") == 0)
+       while ((m = getmntent(fp)) != NULL) {
+               if (strcmp(m->mnt_type, "debugfs") == 0) {
+                       strcpy(debugfs, m->mnt_dir);
+                       debugfs_found = 1;
                        break;
+               }
        }
-       fclose(fp);
 
-       if (strcmp(type, "debugfs") != 0)
-               die("debugfs not mounted, please mount");
+       endmntent(fp);
 
-       debugfs_found = 1;
+       if (!debugfs_found)
+               die("debugfs not mounted, please mount");
 
        return debugfs;
 }
@@ -317,7 +318,8 @@ static void copy_event_system(const char *sys, struct tracepoint_path *tps)
                die("can't read directory '%s'", sys);
 
        while ((dent = readdir(dir))) {
-               if (strcmp(dent->d_name, ".") == 0 ||
+               if (dent->d_type != DT_DIR ||
+                   strcmp(dent->d_name, ".") == 0 ||
                    strcmp(dent->d_name, "..") == 0 ||
                    !name_in_tp_list(dent->d_name, tps))
                        continue;
@@ -334,7 +336,8 @@ static void copy_event_system(const char *sys, struct tracepoint_path *tps)
 
        rewinddir(dir);
        while ((dent = readdir(dir))) {
-               if (strcmp(dent->d_name, ".") == 0 ||
+               if (dent->d_type != DT_DIR ||
+                   strcmp(dent->d_name, ".") == 0 ||
                    strcmp(dent->d_name, "..") == 0 ||
                    !name_in_tp_list(dent->d_name, tps))
                        continue;
@@ -394,26 +397,21 @@ static void read_event_files(struct tracepoint_path *tps)
                die("can't read directory '%s'", path);
 
        while ((dent = readdir(dir))) {
-               if (strcmp(dent->d_name, ".") == 0 ||
+               if (dent->d_type != DT_DIR ||
+                   strcmp(dent->d_name, ".") == 0 ||
                    strcmp(dent->d_name, "..") == 0 ||
                    strcmp(dent->d_name, "ftrace") == 0 ||
                    !system_in_tp_list(dent->d_name, tps))
                        continue;
-               sys = malloc_or_die(strlen(path) + strlen(dent->d_name) + 2);
-               sprintf(sys, "%s/%s", path, dent->d_name);
-               ret = stat(sys, &st);
-               free(sys);
-               if (ret < 0)
-                       continue;
-               if (S_ISDIR(st.st_mode))
-                       count++;
+               count++;
        }
 
        write_or_die(&count, 4);
 
        rewinddir(dir);
        while ((dent = readdir(dir))) {
-               if (strcmp(dent->d_name, ".") == 0 ||
+               if (dent->d_type != DT_DIR ||
+                   strcmp(dent->d_name, ".") == 0 ||
                    strcmp(dent->d_name, "..") == 0 ||
                    strcmp(dent->d_name, "ftrace") == 0 ||
                    !system_in_tp_list(dent->d_name, tps))
@@ -422,10 +420,8 @@ static void read_event_files(struct tracepoint_path *tps)
                sprintf(sys, "%s/%s", path, dent->d_name);
                ret = stat(sys, &st);
                if (ret >= 0) {
-                       if (S_ISDIR(st.st_mode)) {
-                               write_or_die(dent->d_name, strlen(dent->d_name) + 1);
-                               copy_event_system(sys, tps);
-                       }
+                       write_or_die(dent->d_name, strlen(dent->d_name) + 1);
+                       copy_event_system(sys, tps);
                }
                free(sys);
        }