Re: [PATCH 0/3] x86/mce: Fix more noinstr fun

[Borislav Petkov]

On Fri, Feb 04, 2022 at 12:24:00PM +0100, Marco Elver wrote:
> I guess to solve noinstr "calling" something else the only solution is
> to make the other function noinstr as well, or __always_inline.
> 
> Have you considered making some of these other functions 'noinstr' as
> well? I guess __always_inline works, esp. if there's just 1 caller.
> And by the looks of it you're getting a net .text reduction, so

Yeah, I started doing that and the savings were the persuasive
argument.

Even more so if the function has one caller only and gets inlined,
normally. I guess it doesn't get inlined when there's KASAN
instrumentation or so but I haven't verified it fully why.

Because even for oneliners like v8086_mode() which should get inlined
trivially, the compiler ends up doing this constprop thing - I guess
some constants folding optimization thing... it probably doesn't even
matter so much whether oneliners get inlined in KASAN-enabled builds so
I guess we might just as well force-inline them for the other configs.

> Acked-by: Marco Elver <elver@xxxxxxxxxx>

Thx.

-- 
Regards/Gruss,
    Boris.

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