[PATCH 1/3] kexec: don't invoke OOM-killer for control page allocation

[Baoquan He]

On 04/18/16 at 06:12pm, Baoquan He wrote:
> On 04/18/16 at 09:39am, Russell King - ARM Linux wrote:
> > On Mon, Apr 18, 2016 at 01:32:53PM +0800, Baoquan He wrote:
> > > On 04/14/16 at 09:00pm, Russell King wrote:
> > > > If we are unable to find a suitable page when allocating the control
> > > > page, do not invoke the OOM-killer: killing processes probably isn't
> > > > going to help.
> > > 
> > > Originally kexec was made to reboot to test kernel quickly. If 1st
> > > kernel is palyed and hurted in a bad state and developer want to discard
> > > it and take a quick reboot, why don't we have a best try to make a
> > > successful kexec load?
> > 
> > And if it kills off every process trying to get a suitable page,
> > which then means you can't do anything other than power cycle,
> > that's okay?
> 
> Yes, I agree on that it's non-sense if every process is killed. But will
> each kexec load which need OOM-killer go that far? And there's only one
> page (if 32 bit) or 2 pages (if 64 bit) for control page, it may not
> need kill that many processes to pick one.

Sorry, I was wrong. Those control pages are imtermediate pages which
is used to copy kenrel and initrd from user buffer to their final place,
they should be dozens of MB. So I am fine with this change, ack it.

Acked-by: Baoquan He <bhe at redhat.com>

Thanks
Baoquan