eal: cache last directory permissions checked

When loading a directory of drivers, we check the same hierarchy multiple
times. If we just cache the last directory checked, this avoids repeated
checks of the same path, since all drivers in that path have been added to
the list consecutively.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>

diff --git a/lib/librte_eal/common/eal_common_options.c b/lib/librte_eal/common/eal_common_options.c
index 6c63b93..85d5ba7 100644 (file)
--- a/lib/librte_eal/common/eal_common_options.c
+++ b/lib/librte_eal/common/eal_common_options.c
@@ -414,11 +414,17 @@ verify_perms(const char *dirpath)
 
        /* if not root, check down one level first */
        if (strcmp(dirpath, "/") != 0) {
+               static __thread char last_dir_checked[PATH_MAX];
                char copy[PATH_MAX];
+               const char *dir;
 
                strlcpy(copy, dirpath, PATH_MAX);
-               if (verify_perms(dirname(copy)) != 0)
-                       return -1;
+               dir = dirname(copy);
+               if (strncmp(dir, last_dir_checked, PATH_MAX) != 0) {
+                       if (verify_perms(dir) != 0)
+                               return -1;
+                       strlcpy(last_dir_checked, dir, PATH_MAX);
+               }
        }
 
        /* call stat to check for permissions and ensure not world writable */