please fix FUSION (Was: [v3.13][v3.14][Regression]kthread:makekthread_create()killable)

[Thomas Gleixner]

On Sat, 22 Mar 2014, Thomas Gleixner wrote:
> On Sat, 22 Mar 2014, Oleg Nesterov wrote:
> > Personally I dislike this change. In fact I think it is ugly. But this
> > is only my opinion.
> 
> It's not only ugly, it's activly wrong. It's as wrong as 786235ee
> itself. And 786235ee needs to be reverted and the revert must go into
> 3.13.stable as well. I'll send a revert request in separate mail.

Sorry. I misread the combo of both patches. 786235ee is correct. We
definitely don't want to revert it. 

But I still think, that changing this to butt ugly heuristics with an
arbitrary chosen timeout is not the proper solution to "fix" a driver
problem and to work around a systemd policy which mandates that
modprobe must return in 30 seconds.

But then systemd/udev mutters:

   "You migh be able to work around the timeout with udev rules and
    OPTIONS+="event_timeout=120", but that code was maybe never used
    or tested, so it might not work correctly." [1]

AFAICT from the ubuntu bug system [2] nobody bothered even to try that.

And if the udev/systemd event_timeout option is broken it's way better
to fix that one instead of hacking random heuristics into the kernel.

Thanks,

	tglx

[1] http://lists.freedesktop.org/archives/systemd-devel/2014-March/018007.html
[2] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1276705