Hi Willy,
On Fri, Dec 22, 2017 at 2:09 PM, Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote:
> On Fri, Dec 22, 2017 at 01:30:51PM +0100, Geert Uytterhoeven wrote:
>> On Fri, Dec 22, 2017 at 1:28 PM, Geert Uytterhoeven
>> <geert@xxxxxxxxxxxxxx> wrote:
>> > On Fri, Dec 22, 2017 at 4:55 AM, Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote:
>> >> What alignment can we rely on for function pointers?
>> >
>> > Only one bit to steal on m68k...
>>
>> Same on SH.
>
> How much damage would we do by adding -falign-functions=4 to CFLAGS
> on m68k? Can you measure that for me?
With defconfig (aka multi_defconfig) and gcc 4.1.2:
text data bss dec hex filename
3594487 959460 186492 4740439 485557 vmlinux.old
3611159 959484 185724 4756367 48938f vmlinux
text +16672
data +24
bss -768 (why?)
total +15928
Given kernel size increased on average almost 50 KiB between
v4.x and v4.(x+1), the damage wouldn't be that bad ;-)
Note that this aligned C functions only. Assembler code (incl. the '040 and
'060 integer/floating point support packages) still has to be fixed.
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
