Messages in this thread | | | Date | Thu, 14 Nov 2013 12:40:39 +0100 | From | Oleg Nesterov <> | Subject | Re: kmod: avoid propagating PF_NO_SETAFFINITY into userspace child |
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On 11/14, Tejun Heo wrote: > > Hello, > > On Thu, Nov 14, 2013 at 09:51:47AM +0800, zhang.yi20@zte.com.cn wrote: > > The kernel worker thread has the PF_NO_SETAFFINITY flag, and it is propagated > > into the userspace child. Clearing this flag in usersapce child to enable its > > migrating capability. > > > > > > Signed-off-by: Zhang Yi <zhang.yi20@zte.com.cn> > > > > --- linux3-12/kernel/kmod.c 2013-11-14 09:06:58.991781656 +0000 > > +++ linux3-12/kernel/kmod.c 2013-11-14 09:08:47.511781621 +0000 > > @@ -217,6 +217,7 @@ static int ____call_usermodehelper(void > > * Avoid propagating that into the userspace child. > > */ > > set_user_nice(current, 0); > > + current->flags &= ~PF_NO_SETAFFINITY; > > I'm a bit confused. kernel_thread() doesn't use workqueue or > kthread_bind(),
Yes, but kernel_thread() is called by the worker thread which has PF_NO_SETAFFINITY, this flag is copied to child->flags.
Looks like Zhang is right... But I'd suggest to change flush_old_exec() instead (see "current->flags &= ...").
Oleg.
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