Messages in this thread |  | | | Date | Tue, 8 May 2012 15:51:16 -0700 | | From | Andrew Morton <> | | Subject | Re: [PATCH 3/3] pidns: Make killed children autoreap |
| |
On Sun, 06 May 2012 17:35:46 -0700 ebiederm@xmission.com (Eric W. Biederman) wrote:
> > 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. > > Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> > --- > kernel/pid_namespace.c | 7 ++++++- > 1 files changed, 6 insertions(+), 1 deletions(-) > > diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c > index 57bc1fd..b98b0ed 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);
Taking a lock around a single atomic write is always fishy. What exactly is this locking here for?
|  |