On Fri, 05 Aug 2016 18:01:13 +0200 Arnd Bergmann <a...@arndb.de> wrote:
> On Friday, August 5, 2016 10:26:25 PM CEST Nicholas Piggin wrote: > > On Fri, 05 Aug 2016 12:17:27 +0200 > > Arnd Bergmann <a...@arndb.de> wrote: > > > > and I also get link errors for the .text.fixup section > > > for any users of __put_user() in really large kernels: > > > net/batman-adv/batman-adv.o:(.text.fixup+0x4): relocation truncated to > > > fit: R_ARM_JUMP24 against `.text.batadv_log_read' > > > > This may be fixed by fixing the linker script to bring in the new > > sections properly (see new patchset). > > > > If not, then if you can combine the sections rather than have them > > consecutive in the output, e.g.,: > > > > *(.text .text.fixup) > > > > Rather than > > > > *(.text) > > *(.text.fixup) > > > > Then the linker has more freedom to rearrange them. I realize it's > > not that simple with ARM's .text.fixup, but maybe that helps you > > get it to work. > > This did the trick: > > diff --git a/include/asm-generic/vmlinux.lds.h > b/include/asm-generic/vmlinux.lds.h > index 0ec807d69f18..7a3ad269fa23 100644 > --- a/include/asm-generic/vmlinux.lds.h > +++ b/include/asm-generic/vmlinux.lds.h > @@ -433,7 +433,7 @@ > * during second ld run in second ld pass when generating System.map */ > #define TEXT_TEXT \ > ALIGN_FUNCTION(); \ > - *(.text.hot .text .text.fixup .text.unlikely) \ > + *(.text.hot .text .text.* .text.fixup .text.unlikely) \ > *(.ref.text) \ > MEM_KEEP(init.text) \ > MEM_KEEP(exit.text) \ > > > It also got much faster again, the link time for an allyesconfig > kernel is now 18 minutes instead of 10 hours, but it's still > much worse than the 2 minutes I had earlier or the four minutes > with the previous patch. Are you using the patches I just sent? Either way, you also need to do the same for data and bss sections as you are using -fdata-sections too. I've found virtually no build time regression on powerpc or x86 when those are taken care of properly (x86 numbers I sent are typo, it's not 5m20, it's 5m02). Thanks, Nick
