Re: sched/fair: Hard lockup from idle_balance()/task_numa_migrate() race

From: Ed Swierk
Date: Fri Nov 03 2017 - 11:23:30 EST


On Fri, Nov 3, 2017 at 8:03 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> I suspect that you'd get more responses if it was an upstream kernel
> (and preferably newer), or even a distro one.
>
> If you run the grsec patches, you need to go to grsec to get support.
> We don't even know what they are doing, since they're hiding their
> patches and not breaking them out.

I understand--we are also not keen on the way grsec distributes their
patches or the timeliness with which they follow stable/LTS kernel
releases.

In this case, I can't conceive of a way to reproduce the problem with
an upstream kernel or any other, yet to my limited understanding of
the evidence it appears there may indeed be a real problem lurking in
there.

I will follow up with the grsec folks.

> On Thu, Nov 2, 2017 at 5:51 PM, Ed Swierk <eswierk@xxxxxxxxxxxxxxxxxx> wrote:
>> Ping?
>>
>> On Wed, Oct 25, 2017 at 9:35 PM, Ed Swierk <eswierk@xxxxxxxxxxxxxxxxxx> wrote:
>>>
>>> Ping?
>>>
>>> On Mon, Oct 16, 2017 at 4:11 PM, Ed Swierk <eswierk@xxxxxxxxxxxxxxxxxx> wrote:
>>> >
>>> > Ping for Peter, Ingo and other sched maintainers:
>>> >
>>> > I'd appreciate any feedback on this hard lockup issue, which occurred
>>> > on a system running kernel 4.4.52-grsec.

Thanks,
--Ed