On Sun, Aug 07, 2016 at 10:26:19PM +0200, Arnd Bergmann wrote: > On Sunday, August 7, 2016 7:27:39 PM CEST Alan Modra wrote: > > > > If it can, then Nicholas' patch should be: > > > > *(.text.hot .text.hot.*) *(.text.unlikely .text.unlikely.*) *(.text > > .text.*) > > > > If you can't put .text.fixup too far away then you may as well just use > > > > *(.text .text.*) > > I tried this version: > > diff --git a/include/asm-generic/vmlinux.lds.h > b/include/asm-generic/vmlinux.lds.h > index b1f8828e9eac..fc210dacac9a 100644 > --- a/include/asm-generic/vmlinux.lds.h > +++ b/include/asm-generic/vmlinux.lds.h > @@ -438,7 +438,9 @@ > * 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.*) \ > + *(.text.hot .text.hot.*) \ > + *(.text.unlikely .text.fixup .text.unlikely.*) \ > + *(.text .text.*) \ > *(.ref.text) \ > MEM_KEEP(init.text) \ > MEM_KEEP(exit.text) \ > > but that failed to link an allyesconfig kernel because of references > from .fixup to .text.*. Trying your version now:
Well then, that proves you can't put .text.fixup too far aways from the associated input section. > *(.text.hot .text.hot.*) *(.text.unlikely .text.unlikely.*) *(.text .text.*) Which means this is guaranteed to fail when you test it properly using gcc's profiling options, in order to generate .text.hot* and/or .text.unlikely* sections. It seems to me the right thing to do would be to change kernel asm to generate .text.foo.fixup for any .text.foo section. A gas feature available with binutils-2.26 enabled by --sectname-subst might help with implementing that. -- Alan Modra Australia Development Lab, IBM
