From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 1 Sep 2015 16:47:46 +0000 (+0200)
Subject: core: when looking for the unit for a process, look at the PID hashmaps first
X-Git-Tag: v226~54^2~3
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=5fe8876b320e9f6355425df9991ac38363684117;p=thirdparty%2Fsystemd.git

core: when looking for the unit for a process, look at the PID hashmaps first

It's cheaper that going to cgroupfs, and also usually the better choice
since it's not racy and can map PIDs even if they were moved to a
different unit.
---

diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index aafd75f424e..e92d2cc850f 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -1005,6 +1005,7 @@ Unit* manager_get_unit_by_cgroup(Manager *m, const char *cgroup) {
 
 Unit *manager_get_unit_by_pid(Manager *m, pid_t pid) {
         _cleanup_free_ char *cgroup = NULL;
+        Unit *u;
         int r;
 
         assert(m);
@@ -1012,6 +1013,14 @@ Unit *manager_get_unit_by_pid(Manager *m, pid_t pid) {
         if (pid <= 1)
                 return NULL;
 
+        u = hashmap_get(m->watch_pids1, LONG_TO_PTR(pid));
+        if (u)
+                return u;
+
+        u = hashmap_get(m->watch_pids2, LONG_TO_PTR(pid));
+        if (u)
+                return u;
+
         r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup);
         if (r < 0)
                 return NULL;