Re: [RFC PATCH 11/18] jffs2: Convert jffs2_gcd_mtd kthread into the iterant API

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From	Oleg Nesterov <oleg@redhat.com>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH 11/18] jffs2: Convert jffs2_gcd_mtd kthread into the iterant API
Date	Sun, 07 Jun 2015 00:40:01 +0200
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On 06/06, Jiri Kosina wrote:
>
> On Sat, 6 Jun 2015, Oleg Nesterov wrote:
>
> > Still I personally dislike the new kthread_sigaction() API. I agree,
> > a couple if signal helpers for kthreads make sense. Say,
> >
> > 	void kthread_do_signal_stop(void)
> > 	{
> > 		spin_lock_irq(&curtent->sighand->siglock);
> > 		if (current->jobctl & JOBCTL_STOP_DEQUEUED)
> > 			__set_current_state(TASK_STOPPED);
> > 		spin_unlock_irq(&current->sighand->siglock);
> >
> > 		schedule();
> > 	}
>
> ... not to mention the fact that 'STOP' keyword in relation to kthreads
> has completely different meaning today, which just contributes to overall
> confusion; but that's an independent story.

Yes, agreed.

> > But personally I do not think kthread_do_signal() makes a lot of sense...
>
> Would it be possible for you to elaborate a little bit more why you think
> so ... ?

Please see another email I sent in reply to 06/18.

> I personally don't see a huge principal difference between
> "kthread_signal_dequeue() + kthread_do_signal_{stop,...}" vs. generic
> "kthread_do_signal()" that's just basically completely general and takes
> care of 'everything necessary'.

Then why do we need the new API ?

And I do see the difference. Rightly or not I belive that this API buys
nothing but makes the kthread && signal interaction more complex and
confusing. For no reason.

But!

> That being said, my relationship to signal
> handling code is of course much less intimate compared to yours,

No, no, no, this doesn't matter at all ;)

Yes I do dislike this API. So what? I can be wrong. So if other reviewers
like it I will hate them all ^W^W^W not argure. So please comment. I never
trust myself unless I can technically (try to) prove I am right. In this
case I can't, this is only my feeling.

Oleg.

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Thread

Re: [RFC PATCH 11/18] jffs2: Convert jffs2_gcd_mtd kthread into  the iterant API Oleg Nesterov <oleg@redhat.com> - 2015-06-06 23:20 +0200
  Re: [RFC PATCH 11/18] jffs2: Convert jffs2_gcd_mtd kthread into the  iterant API Jiri Kosina <jkosina@suse.cz> - 2015-06-06 23:40 +0200
    Re: [RFC PATCH 11/18] jffs2: Convert jffs2_gcd_mtd kthread into  the iterant API Oleg Nesterov <oleg@redhat.com> - 2015-06-07 00:40 +0200
      Re: [RFC PATCH 11/18] jffs2: Convert jffs2_gcd_mtd kthread into the  iterant API Jiri Kosina <jkosina@suse.cz> - 2015-06-07 00:50 +0200
        Re: [RFC PATCH 11/18] jffs2: Convert jffs2_gcd_mtd kthread into  the iterant API Oleg Nesterov <oleg@redhat.com> - 2015-06-07 01:10 +0200

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