From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 15 Mar 2011 20:21:38 +0000 (+0100)
Subject: cgroup: don't recheck all the time whether the systemd hierarchy is mounted, to make... 
X-Git-Tag: v21~75
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=0ac10822732008aa2c0af7a0499c838446ac0a82;hp=8f7a3c1402a8de36b2c63935358a53510d2fe7c1;ds=sidebyside

cgroup: don't recheck all the time whether the systemd hierarchy is mounted, to make strace outputs nicer and save a few stat()s
---

diff --git a/src/cgroup-util.c b/src/cgroup-util.c
index bbadc789a..090573bd3 100644
--- a/src/cgroup-util.c
+++ b/src/cgroup-util.c
@@ -484,6 +484,7 @@ int cg_get_path(const char *controller, const char *path, const char *suffix, ch
         const char *p;
         char *mp;
         int r;
+        static __thread bool good = false;
 
         assert(controller);
         assert(fs);
@@ -504,9 +505,14 @@ int cg_get_path(const char *controller, const char *path, const char *suffix, ch
         if (asprintf(&mp, "/sys/fs/cgroup/%s", p) < 0)
                 return -ENOMEM;
 
-        if ((r = path_is_mount_point(mp)) <= 0) {
-                free(mp);
-                return r < 0 ? r : -ENOENT;
+        if (!good) {
+                if ((r = path_is_mount_point(mp)) <= 0) {
+                        free(mp);
+                        return r < 0 ? r : -ENOENT;
+                }
+
+                /* Cache this to save a few stat()s */
+                good = true;
         }
 
         if (path && suffix)