RE: [PATCH 1/1] PM: Thaws refrigerated and to be exited kernelthreads

[Dasgupta, Romit]

> Subject: Re: [PATCH 1/1] PM: Thaws refrigerated and to be exited kernel
> threads
> 
> Hi!
> 
> > Kicks out a frozen thread from the refrigerator when an active thread has
> > invoked kthread_stop on the frozen thread.
> >
> > Signed-off-by: Romit Dasgupta <romit@xxxxxx>
> > ---
> >
> > diff --git a/kernel/freezer.c b/kernel/freezer.c
> > index bd1d42b..c28dbe8 100644
> > --- a/kernel/freezer.c
> > +++ b/kernel/freezer.c
> > @@ -9,6 +9,7 @@
> >  #include <linux/module.h>
> >  #include <linux/syscalls.h>
> >  #include <linux/freezer.h>
> > +#include <linux/kthread.h>
> >
> >  /*
> >   * freezing is complete, mark current process as frozen
> > @@ -49,7 +50,7 @@ void refrigerator(void)
> >
> >  	for (;;) {
> >  		set_current_state(TASK_UNINTERRUPTIBLE);
> > -		if (!frozen(current))
> > +		if (!frozen(current) || (!current->mm && kthread_should_stop()))
> >  			break;
> >  		schedule();
> 
> Well, what if the thread does some processing before stopping? That
> would break refrigerator assumptions...

The suspend thread will block until the 'to be stopped' thread clears up. That is what any call to kthread_stop would boil down to. The target thread would anyway be out of the refrigerator so I am not sure what assumption you mean here. Eventually, the target thread would clear up and wake up the suspend thread and then things would go on as usual.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/