Re: [PATCH 2/2] mm: page_alloc: Add unlikely for MAX_ORDER check

[이승훈 <waydi1@gmail.com>]

I submit the patch to make sure "order >= MAX_ORDER" happen unlikely.

But, I couldn't think generated code by compiler.

I think I was wrong.

Thanks your comments.

2013/7/31 Dave Hansen <dave.hansen@intel.com>:
> Cody, it's a good point that we shouldn't be looking at something as
> simplistic as the file sizes.  I also used whole vmlinux's and turned
> off debuginfo:
>
>    text    data     bss     dec     hex filename
> 10064322        1980968 3051520 15096810         e65bea vmlinux.nothing
> 10064451        1980968 3051520 15096939         e65c6b vmlinux.unlikely
>
> So it still cost ~130 bytes of text.  Also, perusing the vmlinux
> objdump, adding the unlikely() does look to take
> __alloc_pages_direct_compact and move it _closer_ to the page allocation
> code.
>
> What does this all mean?  Hell if I know.  It's up to the patch
> submitter to explain the implications of the patch. ;)
>
>

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>