Re: [PATCH] mm/vma: Append unlikely() while testing VMA access permissions
From: Geert Uytterhoeven
Date: Mon Feb 24 2020 - 05:10:11 EST
Hi Anshuman,
Thanks for your patch!
On Mon, Feb 24, 2020 at 7:22 AM Anshuman Khandual
<anshuman.khandual@xxxxxxx> wrote:
> It is unlikely that an inaccessible VMA without required permission flags
> will get a page fault. Hence lets just append unlikely() directive to such
Why? Isn't it the idea that you get a page fault when the page is not
accessible?
> checks in order to improve performance while also standardizing it across
> various platforms.
Does it make a difference to add these? Have you benchmarked this?
https://lwn.net/Articles/420019/
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds