From: Eric W. Biederman Date: Thu, 31 May 2012 23:26:40 +0000 (-0700) Subject: pidns: make killed children autoreap X-Git-Tag: firefly_0821_release~3680^2~2684^2~12 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=00c10bc13cdb58447d6bb2a003afad7bd60f5a5f;p=firefly-linux-kernel-4.4.55.git pidns: make killed children autoreap Force SIGCHLD handling to SIG_IGN so that signals are not generated and so that the children autoreap. This increases the parallelize and in general the speed of network namespace shutdown. Note self reaping childrean can exist past zap_pid_ns_processess but they will all be reaped before we allow the pid namespace init task with pid == 1 to be reaped. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Eric W. Biederman Cc: Oleg Nesterov Cc: Pavel Emelyanov Cc: Cyrill Gorcunov Cc: Louis Rilling Cc: Mike Galbraith Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 57bc1fd35b3c..fd3c44986191 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -149,7 +149,12 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns) { int nr; int rc; - struct task_struct *task; + struct task_struct *task, *me = current; + + /* Ignore SIGCHLD causing any terminated children to autoreap */ + spin_lock_irq(&me->sighand->siglock); + me->sighand->action[SIGCHLD - 1].sa.sa_handler = SIG_IGN; + spin_unlock_irq(&me->sighand->siglock); /* * The last thread in the cgroup-init thread group is terminating.