Re: [PATCH]: exec: avoid propagating PF_NO_SETAFFINITY into userspace child

[Oleg Nesterov <oleg@redhat.com>]

On 11/26, zhang.yi20@zte.com.cn wrote:
>
> Userspace process doesn't want the PF_NO_SETAFFINITY, but its parent may be
> a kernel worker thread which has PF_NO_SETAFFINITY set.

... and this worker thread can do kernel_thread() to create the child.

> Clearing this flag in usersapce child to enable its migrating capability.
>
>
> Signed-off-by: Zhang Yi <zhang.yi20@zte.com.cn>
>
> --- linux-3.12.old/fs/exec.c	2013-11-26 08:53:12.175811856 +0000
> +++ linux-3.12/fs/exec.c	2013-11-26 09:26:53.575999604 +0000
> @@ -1091,7 +1091,8 @@ int flush_old_exec(struct linux_binprm *
>
>  	set_fs(USER_DS);
>  	current->flags &=
> -		~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD | PF_NOFREEZE);
> +		~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD | PF_NOFREEZE
> +		| PF_NO_SETAFFINITY);

Thanks,

Acked-by: Oleg Nesterov <oleg@redhat.com>




Can't resist... perhaps

	current->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD |
			    PF_NOFREEZE | PF_NO_SETAFFINITY);

looks a bit better, but this is minor and I won't insist.

Oleg.