Re: [PATCH 1/2] x86/nmi: Optimize the check for being in the repeat_nmi code

From: Andy Lutomirski
Date: Fri Mar 10 2017 - 14:04:24 EST


On Fri, Mar 10, 2017 at 11:00 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Thu, Mar 9, 2017 at 11:20 PM, Ingo Molnar <mingo@xxxxxxxxxx> wrote:
>>
>> Joking aside, I'll bite: while in the kernel we try to avoid ever actually
>> _writing_ new assembly code
>
> .. also, when we do, I think we should care about it.
>
> If you write asm, and the end result is noticeably worse than what
> your average compiler would generate, exactly why are you writing it
> in asm in the first place?
>
> So I think people should aim to avoid asm. Andy certainly knows that,
> and I loved his "rewrite a lot of the low-level system call code"
> patches.
>
> But the corollary to that is that if you _do_ write assembler, please
> have some pride in the code, and don't half-arse it.
>

Geez, I didn't expect anyone to take my silly comment remotely
seriously :) And I do like Steven's patches.

--Andy, who just looked at binutils source to figure out WTF "nobits"
meant. Take that, asm!