Re: [PATCH] x86/cpufeature: guard asm_volatile_goto usage with CC_HAVE_ASM_GOTO

Yonghong Song
2018-04-14T20:31:55Z

On 4/14/18 3:11 AM, Peter Zijlstra wrote:
> On Fri, Apr 13, 2018 at 01:42:14PM -0700, Alexei Starovoitov wrote:
>> On 4/13/18 11:19 AM, Peter Zijlstra wrote:
>>> On Tue, Apr 10, 2018 at 02:28:04PM -0700, Alexei Starovoitov wrote:
>>>> Instead of
>>>> #ifdef CC_HAVE_ASM_GOTO
>>>> we can replace it with
>>>> #ifndef __BPF__
>>>> or some other name,
>>>
>>> I would prefer the BPF specific hack; otherwise we might be encouraging
>>> people to build the kernel proper without asm-goto.
>>>
>>
>> I don't understand this concern.
>
> The thing is; this will be a (temporary) BPF specific hack. Hiding it
> behind something that looks 'normal' (CC_HAVE_ASM_GOTO) is just not
> right.

This is a fair concern. I will use a different macro and send v2 soon.
Thanks.