Re: [PATCH HACK RFC] cpu: Prevent late-arriving interrupts from disrupting offline

From: Dietmar Eggemann
Date: Tue Jun 04 2019 - 09:33:32 EST

On 6/4/19 9:45 AM, Paul E. McKenney wrote:
On Mon, Jun 03, 2019 at 03:39:18PM +0200, Dietmar Eggemann wrote:
On 6/3/19 1:44 PM, Mark Rutland wrote:
On Mon, Jun 03, 2019 at 10:38:48AM +0200, Peter Zijlstra wrote:
On Sat, Jun 01, 2019 at 06:12:53PM -0700, Paul E. McKenney wrote:
Scheduling-clock interrupts can arrive late in the CPU-offline process,


05981277a4de1ad6 ("arm64: Use common outgoing-CPU-notification code")

... but it looks like Paul's patch to do so [1] fell through the cracks;
I'm not aware of any reason that shouldn't have been taken.

Paul, do you want to resend that?

Please do. We're carrying this patch out-of-tree for while now in
our EAS integration to get cpu hotplug tests passing on TC2 (arm).

Huh. It still applies. But I have no means of testing it.

We can do the testing part on our TC2 platform, i.e. we're testing it with each of our EAS mainline integration right now.;a=commit;h=8cd16f1dc2cd896a0b1e2010b4992b33fdc11fe0

And it looks like the reason I dropped it was that I didn't get any
response from the maintainer. I sent a message to this effect to
linux-arm-kernel@xxxxxxxxxxxxxxxxxxx and linux@xxxxxxxxxxxxxxxx on May
21, 2015.

So here it is again. ;-)

I have queued this locally. Left to myself, I add the two of you on its
Cc: list and run it through my normal process. But given the history,
I would still want either an ack from the maintainer or, better, for
the maintainer to take the patch.

Or is there a better way for us to proceed on this?

You could send this patch also to linux-arm-kernel@xxxxxxxxxxxxxxxxxxx and cc rmk to get his opinion on the patch.