Re: [patch V2 22/29] lockup_detector: Make watchdog_nmi_reconfigure() two stage

On Tue, Oct 03, 2017 at 07:27:01PM +0000, Thomas Gleixner wrote:

On Tue, 3 Oct 2017, Thomas Gleixner wrote:

quoted

On Tue, 3 Oct 2017, Thomas Gleixner wrote:

quoted

On Tue, 3 Oct 2017, Michael Ellerman wrote:

quoted

Hmm, I tried that patch, it makes the warning go away. But then I
triggered a deliberate hard lockup and got nothing.

Then I went back to the existing code (in linux-next), and I still get
no warning from a deliberate hard lockup.

So seems there may be some more gremlins. Will test more in the morning.

Hrm. That's weird. I'll have a look and send a proper patch series on top
of next.

The major difference is that the reworked code utilizes
watchdog_nmi_reconfigure() for both init and the sysctl updates, but I
can't for my life figure out why that doesn't work.

I collected the changes which Linus requested along with the nmi_probe()
one and pushed them into:

 git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git WIP.core/urgent

That's based on 4.13 final so it neither contains 4.14 nor -next material.

Tested your changes on 4.14-rc3 and it passes my tests.  Thanks!

Tested-and-Reviewed-by: Don Zickus [off-list ref]