Re: [RFC v2 3/6] kthread: warn on kill signal if not OOM

From: Pavel Machek
Date: Mon Sep 22 2014 - 15:49:18 EST


On Thu 2014-09-11 13:23:54, Dmitry Torokhov wrote:
> On Thu, Sep 11, 2014 at 12:59:25PM -0700, James Bottomley wrote:
> >
> > On Tue, 2014-09-09 at 16:01 -0700, Dmitry Torokhov wrote:
> > > On Tuesday, September 09, 2014 03:46:23 PM James Bottomley wrote:
> > > > On Wed, 2014-09-10 at 07:41 +0900, Tejun Heo wrote:
> > > > >
> > > > > The thing is that we have to have dynamic mechanism to listen for
> > > > > device attachments no matter what and such mechanism has been in place
> > > > > for a long time at this point. The synchronous wait simply doesn't
> > > > > serve any purpose anymore and kinda gets in the way in that it makes
> > > > > it a possibly extremely slow process to tell whether loading of a
> > > > > module succeeded or not because the wait for the initial round of
> > > > > probe is piggybacked.
> > > >
> > > > OK, so we just fire and forget in userland ... why bother inventing an
> > > > elaborate new infrastructure in the kernel to do exactly what
> > > >
> > > > modprobe <mod> &
> > > >
> > > > would do?
> > >
> > > Just so we do not forget: we also want the no-modules case to also be able
> > > to probe asynchronously so that a slow device does not stall kernel booting.
> >
> > Yes, but we mostly do this anyway. SCSI for instance does asynchronous
> > scanning of attached devices (once the cards are probed)
>
> What would it do it card was a bit slow to probe?
>
> > but has a sync
> > point for ordering.
>
> Quite often we do not really care about ordering of devices. I mean,
> does it matter if your mouse is discovered before your keyboard or
> after?

Actually yes, I suspect it does.

I do evtest /dev/input/eventX by hand, occassionaly. It would be
annoying if they moved between reboots.
Pavel

--
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