On Sat, Feb 15, 2014 at 9:44 AM, Andi Kleen <andi@xxxxxxxxxxxxxx> wrote: > On Sat, Feb 15, 2014 at 02:38:14PM +0100, Markus Trippelsdorf wrote: >> On 2014.02.14 at 22:21 +0100, Andi Kleen wrote: >> > This is the updated LTO patchkit for 3.14-rc2. LTO allows >> > the compiler to do global optimization over the whole kernel. >> >> It is mildly annoying that one couldn't use vanilla binutils. Have you >> already opened bugs on sourceware.org/bugzilla/ to get this fixed for >> gold and ld.bfd? > > The problem is supporting "pass through" of both pure (.S) assembler code and > LTO through ld -r, because the kernel makefiles use ld -r heavily. > Standard binutils would throw all the assembler away when in plugin LTO > mode. > > HJ did the work (and fixed a couple other bugs that blocked kernel LTO), > but the mainline binutils people rejected the patches. You can judge > for yourself if their reasons make sense: > > https://sourceware.org/ml/binutils/2012-05/msg00057.html > > Noone has done the work for gold so far. > > There was some effort from the Fedora binutils maintainers to add the > necessary patches to their version, but at least what is in FC20 doesn't > seem to be enough. There are some additional LTO bug fixes in my Linux binutils. -- H.J. -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
