> > On Mon, 2018-01-08 at 18:42 +0100, Peter Zijlstra wrote: > > On Mon, Jan 08, 2018 at 09:28:12AM -0800, Tim Chen wrote: > > > On 01/08/2018 08:14 AM, Peter Zijlstra wrote: > > > > On Mon, Jan 08, 2018 at 01:47:07PM +0100, Peter Zijlstra wrote: > > > >>> a good suggestion, but we encountered some issues with it either > > > >>> crashing the kernel at boot or not properly turning on/off. > > > > > > > > The below boots, but I lack stuff to test the enabling. > > > > > > Peter, > > > > > > Thanks. Will give it a spin. One other concern is if JUMP_LABEL is > > > not configured, this may not work, and we may still need fall back > > > to a control variable. > > > > Urgh yes.. I always forget about that case. Will the retpoline crud be > > backported to a GCC old enough to not have asm-goto? If not, we could > > make all of this simply require asm-goto. > > I think HJ said he was planning to backport as far as 4.9. When was asm- > goto added?
It was added to GCC 4.5. H.J.
