linux-kernel - Re: [PATCH 2/3] livepatch: send a fake signal to all blocking tasks

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Date:   Wed, 24 May 2017 10:31:27 +0200 (CEST)
From:   Miroslav Benes <mbenes@...e.cz>
To:     Josh Poimboeuf <jpoimboe@...hat.com>
cc:     jeyu@...hat.com, jikos@...nel.org, pmladek@...e.com,
        live-patching@...r.kernel.org, linux-kernel@...r.kernel.org,
        Oleg Nesterov <oleg@...hat.com>
Subject: Re: [PATCH 2/3] livepatch: send a fake signal to all blocking
 tasks

On Tue, 23 May 2017, Josh Poimboeuf wrote:

> On Thu, May 18, 2017 at 02:00:42PM +0200, Miroslav Benes wrote:
> > @@ -551,3 +551,43 @@ void klp_copy_process(struct task_struct *child)
> >  
> >  	/* TIF_PATCH_PENDING gets copied in setup_thread_stack() */
> >  }
> > +
> > +/*
> > + * Sends a fake signal to all non-kthread tasks with TIF_PATCH_PENDING set.
> > + * Kthreads with TIF_PATCH_PENDING set are woken up. Only admin can request this
> > + * action currently.
> > + */
> > +void klp_send_fake_signal(void)
> > +{
> > +	struct task_struct *g, *task;
> > +
> > +	pr_info("sending a fake signal and waking sleeping kthreads up\n");
> 
> Maybe this should be pr_notice(), for consistency with our other
> printks.
> 
> Also I wonder if the message can be made more meaningful to the user.
> The "fake" part of the signal and the "waking sleeping kthreads" bit
> could be too much information for the user, IMO.  How about "signaling
> remaining tasks"?  Just an idea.

Good one. I'll change it in v2.

Thanks,
Miroslav