Re: [PATCH v2] x86/head64: micro optimization: use memset instead of for loop

From: Ingo Molnar
Date: Tue Feb 09 2016 - 08:18:46 EST



* Alexander Kuleshov <kuleshovmail@xxxxxxxxx> wrote:

> This patch simplifies clearing of page table directories, by
> the using of the fast memset() from the arch/x86/lib/memset_64.S.
> Besides this, we 25 bytes is 25 bytes less than original.
>
> text data bss dec hex filename
>
> 9735144 4970776 15474688 30180608 1cc8500 vmlinux.old
> 9735119 4970776 15474688 30180583 1cc84e7 vmlinux
>
> Signed-off-by: Alexander Kuleshov <kuleshovmail@xxxxxxxxx>
> ---
> Changelog:
>
> v2: We got sizeof pud_p/pmd_p in the v1, but actually we need
> to take sizeof of pud_p/pmd_p pointer, although their sizes are
> the same.

Please send a delta patch (with changelog) as the v1 commit is already deep within
the tip:x86/boot branch.

Thanks,

Ingo