Re: [RFC v2 1/6] x86: introduce kernel restartable sequence

From: Nadav Amit
Date: Thu Jan 03 2019 - 18:56:41 EST


> On Jan 3, 2019, at 3:40 PM, Andi Kleen <ak@xxxxxxxxxxxxxxx> wrote:
>
>> Thanks for the explanations. I donât think it would work (e.g., IRQs). I can
>> avoid generalizing and just detect the "magic sequenceâ of the code, but let
>> me give it some more thought.
>
> If you ask me I would just use compiler profile feedback or autofdo (if your
> compiler has a working version)
>
> The compiler can do a much better job at optimizing this than you ever could.
>
> Manual FDO needs some kernel patching though.

As long as you are willing to profile and build your own kernels. (Profiling
will not tell you if users are about to use IPv4/6).

I also donât see how FDO can support modules.