>>> On 24.05.18 at 22:23, <[email protected]> wrote:
>
> On 05/24/2018 01:53 AM, Jan Beulich wrote:
>>>>> On 24.05.18 at 02:46, <[email protected]> wrote:
>>> Port WARN_ON_ONCE macro from Linux.
>> In such a case you should justify adjustments you've made:
> I can add more details, but have mostly just changed variable names. The
> macro is self explanatory.
>
> Should I just change this to: "Define WARN_ON_ONCE macro to mirror LInux
> functionality"
That would seem better to me.
>>> --- a/xen/include/xen/lib.h
>>> +++ b/xen/include/xen/lib.h
>>> @@ -11,6 +11,19 @@
>>> #define BUG_ON(p) do { if (unlikely(p)) BUG(); } while (0)
>>> #define WARN_ON(p) do { if (unlikely(p)) WARN(); } while (0)
>>>
>>> +#define WARN_ON_ONCE(p) \
>>> +({ \
>>> + static bool __section(".data.unlikely") warned; \
>> Linux uses .data.once. That or .data.cold would seem better to me than
>> .data.unlikely.
> I guess there is not reason to keep this in a specific section. I'll
> just go ahead and remove the section here?
There certainly is a reason: We don't want such variables to sit in the
middle of an otherwise frequently accessed cache line. Hence the "cold"
part of the suggested alternatives name.
Jan
_______________________________________________
Xen-devel mailing list
[email protected]
https://lists.xenproject.org/mailman/listinfo/xen-devel
