[PATCH 2/5] x86: Add -mindirect-branch-loop=

[H.J. Lu]

On Sat, Jan 13, 2018 at 8:34 AM, David Woodhouse <dwmw2@infradead.org> wrote:
> On Sat, 2018-01-13 at 03:11 +0000, Kumar, Venkataramanan wrote:
>>
>> > My original patch uses "lfence".  I was asked to use "pause":
>> >
>> > https://gcc.gnu.org/ml/gcc-patches/2018-01/msg00969.html
>>
>> If everyone is ok, my suggestion is to use  "lfence" as the default
>> loop filler for retpoline.
>>
>> Please confirm.
>
> I have the same response to this as I did to precisely the same request
> in the kernel implementation: I'm OK with it but I'd like an explicit
> approval from Intel, and from Paul Turner at Google who architected the
> retpoline concept in the first place.
>
> cf. https://marc.info/?l=linux-kernel&m=151585246530355
>

There is no urgency on this.  We can take another look AFTER
my current patch set is approved and checked in.


-- 
H.J.