disable the cgroups release agent when shutting down

During shutdown, when we try to clean up all remaining processes, the
kernel will fork new agents every time a cgroup runs empty. These
new processes cause delays in the final SIGTERM, SIGKILL logic.

Apart from that, this should also avoid that the kernel-forked binaries
cause unpredictably timed access to the filesystem which we might need to
unmount.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/core/main.c b/src/core/main.c
index 8b8e110f24..ada0f9d94b 100644
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -1942,6 +1942,10 @@ finish:
                         watchdog_close(true);
                 }
 
+		/* avoid the creation of new processes forked by the kernel; at this
+                 * point, we will not listen to the signals anyway */
+		cg_uninstall_release_agent(SYSTEMD_CGROUP_CONTROLLER);
+
                 execve(SYSTEMD_SHUTDOWN_BINARY_PATH, (char **) command_line, env_block);
                 free(env_block);
                 log_error("Failed to execute shutdown binary, freezing: %m");