lkml.org 
[lkml]   [2012]   [May]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [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?



\
 
 \ /
  Last update: 2012-05-09 01:21    [from the cache]
©2003-2011 Jasper Spaans