[PATCH -mm 1/2] wait_task_stopped: remove unneeded delay_group_leader check

[PATCH -mm 1/2] wait_task_stopped: remove unneeded delay_group_leader check

[Oleg Nesterov]

wait_task_stopped() doesn't need the "delay_group_leader" parameter. If the
child is not traced it must be a group leader. With or without subthreads
->group_stop_count == 0 when the whole task is stopped.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>

--- PT/kernel/exit.c~5_ck_group_stop	2007-11-22 19:08:43.000000000 +0300
+++ PT/kernel/exit.c	2007-11-23 20:31:21.000000000 +0300
@@ -1348,7 +1348,7 @@ static int wait_task_zombie(struct task_
  * the lock and this task is uninteresting.  If we return nonzero, we have
  * released the lock and the system call should return.
  */
-static int wait_task_stopped(struct task_struct *p, int delayed_group_leader,
+static int wait_task_stopped(struct task_struct *p,
 			     int noreap, struct siginfo __user *infop,
 			     int __user *stat_addr, struct rusage __user *ru)
 {
@@ -1362,8 +1362,7 @@ static int wait_task_stopped(struct task
 	if (unlikely(!is_task_stopped_or_traced(p)))
 		goto unlock_sig;
 
-	if (delayed_group_leader && !(p->ptrace & PT_PTRACED) &&
-	    p->signal->group_stop_count > 0)
+	if (!(p->ptrace & PT_PTRACED) && p->signal->group_stop_count > 0)
 		/*
 		 * A group stop is in progress and this is the group leader.
 		 * We won't report until all threads have stopped.
@@ -1519,7 +1518,7 @@ repeat:
 				    !(options & WUNTRACED))
 					continue;
 
-				retval = wait_task_stopped(p, ret == 2,
+				retval = wait_task_stopped(p,
 						(options & WNOWAIT), infop,
 						stat_addr, ru);
 			} else if (p->exit_state == EXIT_ZOMBIE) {

Re: [PATCH -mm 1/2] wait_task_stopped: remove unneeded delay_group_leader check

[Mika Penttilä]

> wait_task_stopped() doesn't need the "delay_group_leader" parameter. If the
> child is not traced it must be a group leader. With or without subthreads
>   
What do you mean "has to be a group leader"? It could be a stopped thread.

> ->group_stop_count == 0 when the whole task is stopped.
>
>   
> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
>
> --- PT/kernel/exit.c~5_ck_group_stop	2007-11-22 19:08:43.000000000 +0300
> +++ PT/kernel/exit.c	2007-11-23 20:31:21.000000000 +0300
> @@ -1348,7 +1348,7 @@ static int wait_task_zombie(struct task_
>   * the lock and this task is uninteresting.  If we return nonzero, we have
>   * released the lock and the system call should return.
>   */
> -static int wait_task_stopped(struct task_struct *p, int delayed_group_leader,
> +static int wait_task_stopped(struct task_struct *p,
>  			     int noreap, struct siginfo __user *infop,
>  			     int __user *stat_addr, struct rusage __user *ru)
>  {
> @@ -1362,8 +1362,7 @@ static int wait_task_stopped(struct task
>  	if (unlikely(!is_task_stopped_or_traced(p)))
>  		goto unlock_sig;
>  
> -	if (delayed_group_leader && !(p->ptrace & PT_PTRACED) &&
> -	    p->signal->group_stop_count > 0)
> +	if (!(p->ptrace & PT_PTRACED) && p->signal->group_stop_count > 0)
>  		/*
>  		 * A group stop is in progress and this is the group leader.
>  		 * We won't report until all threads have stopped.
> @@ -1519,7 +1518,7 @@ repeat:
>  				    !(options & WUNTRACED))
>  					continue;
>  
> -				retval = wait_task_stopped(p, ret == 2,
> +				retval = wait_task_stopped(p,
>  						(options & WNOWAIT), infop,
>  						stat_addr, ru);
>  			} else if (p->exit_state == EXIT_ZOMBIE) {
>
> -
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>
>   

Re: [PATCH -mm 1/2] wait_task_stopped: remove unneeded delay_group_leader check

[Roland McGrath]

Your change looks correct to me.


Thanks,
Roland