Re: [PATCH] realtek: rtl8xxxu: Use const init arrays

From: Joe Perches
Date: Sat Oct 01 2016 - 16:01:12 EST


On Sat, 2016-10-01 at 14:53 -0400, Jes Sorensen wrote:
> Joe Perches <joe@xxxxxxxxxxx> writes:
> > Make the init arrays const to reduce data.
> > $ size drivers/net/wireless/realtek/rtl8xxxu/built-in.o* (allyesconfig: x86-32)
> >   text data bss dec hex filename
> >   80107 13651 58 93816 16e78 drivers/net/wireless/realtek/rtl8xxxu/built-in.o.new
> >   65303 28435 58 93796 16e64 drivers/net/wireless/realtek/rtl8xxxu/built-in.o.old
> In total you grow the kernel by 20 bytes. You reduce the data segment
> substantially while growing the text segment instead.

No, not really. The alignment boundaries move a bit for
this particular compilation. It could go the other way for
a different compiler version or set of CONFIG options.

What's important is multiple pages of .data move to .rodata.