Re: [PATCH] Disable non-ABI-compliant optimisations for live patching
From: Torsten Duwe
Date: Mon Jun 27 2016 - 03:00:06 EST
On Mon, Jun 27, 2016 at 12:39:56AM +0200, Pavel Machek wrote:
> Would it be possible to document which kind of guarantees live
> patching needs from compiler?
Sure, here you go, all required guarantees:
Stick to the ABI.
> I always assumed that whoever is preparing the patch does manual
> investigation to see what needs to be changed and how, but apparantly
> that's not the case, so documentation would be good.
See above for the documentation. Imagine each architecture had a whole
hand-optimised assembler kernel. That would give some performance
improvement, right? Same issue here, only much smaller. It's ultimate
performance vs. maintainability.
HTH,
Torsten