On Tue, Apr 18, 2017 at 03:19:42PM -0500, Josh Poimboeuf wrote: > On Tue, Apr 18, 2017 at 11:52:41AM -0700, Andi Kleen wrote: > > Josh Poimboeuf <[email protected]> writes: > > > > > > The error is working as designed. gcc < 4.6.0 doesn't have -mfentry, so > > > it fails the above check on x86. Can you add a skip rule? It should > > > skip building the following case: > > > > > > x86 && ((gcc < 4.6.0) || (CONFIG_X86_32 and !CONFIG_DYNAMIC_FTRACE)) > > > && CONFIG_FUNCTION_GRAPH_TRACER && CONFIG_CC_OPTIMIZE_FOR_SIZE > > > > This will also break everyone's randconfig builds. The better way > > would be to check this in the Makefile and disable one of the options > > I don't know how to disable a config option from the Makefile like that.
You just don't do something in the Makefile, e.g. don't set the -Os For an example see the LTO Makefile here https://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-misc.git/tree/scripts/Makefile.lto?h=lto-411-1 -Andi
