From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Subject: Re: [RFC v2 3/6] kthread: warn on kill signal if not OOM
Date: Fri, 5 Sep 2014 15:49:17 -0700
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Cc: "Luis R. Rodriguez" <mcgrof@do-not-panic.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Wu Zhangjin <falcon@meizu.com>, Takashi Iwai <tiwai@suse.de>,
	Arjan van de Ven <arjan@linux.intel.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Oleg Nesterov <oleg@redhat.com>, hare@suse.com,
	Andrew Morton <akpm@linux-foundation.org>,
	Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
	Joseph Salisbury <joseph.salisbury@canonical.com>,
	Benjamin Poirier <bpoirier@suse.de>,
	Santosh Rastapur <santosh@chelsio.com>,
	Kay Sievers <kay@vrfy.org>,
	One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>,
	Tim Gardner <tim.gardner@canonical.com>,
	Pierre Fersing <pierre-fersing@pierref.org>,
	Nagalakshmi Nandigama <nagalakshmi.nandigama@avagotech.com>,
	Praveen Krishnamoorthy <praveen.krishnamoorthy@avagotech.com>,
	Sreekanth Reddy <sreekanth.reddy@avagotech.com>,
	Abhijit
To: Tejun Heo <tj@kernel.org>
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On Sat, Sep 06, 2014 at 07:31:39AM +0900, Tejun Heo wrote:
> On Sat, Sep 06, 2014 at 07:29:56AM +0900, Tejun Heo wrote:
> > It is for storage devices which always have guaranteed synchronous
> > probing on module load and well-defined probing order.

Agree about probing order (IIRC that is why we had to revert the
wholesale asynchronous probing a few years back) but totally disagree
about synchronous module loading.

Anyway, I just posted a patch that I think preserves module loading
behavior and solves my issue with built-in modules. It does not help
Luis' issue though (but then I think the main problem is with systemd
being stupid there).

> > Sure, modern
> > setups are a lot more dynamic but I'm quite certain that there are
> > setups in the wild which depend on storage driver loading being
> > synchronous.  We can't simply declare one day that such behavior is
> > broken and break, most likely, their boots.
> 
> To add a bit, if the argument here is that dependency on such behavior
> shouldn't exist and module loading and device probing should always be
> asynchronous, the right approach is implementing "synchronous_probing"
> flag not the other way around.  I actually wouldn't hate to see that
> change happening but whoever submits and routes such a change should
> be ready for a major shitstorm, I'm afraid.

I think we already had this storm and that is why here we have opt-in
behavior for the drivers.

Thanks.

-- 
Dmitry