Re: XDP socket rings, and LKMM litmus tests

maranget
2021-03-04T15:46:11Z

> On 3 Mar 2021, at 21:22, Alan Stern <stern@rowland.harvard.edu> wrote:
>
>>>
>>> Local variables absolutely should be treated just like CPU registers, if
>>> possible. In fact, the compiler has the option of keeping local
>>> variables stored in registers.
>>>
>>> (Of course, things may get complicated if anyone writes a litmus test
>>> that uses a pointer to a local variable, Especially if the pointer
>>> could hold the address of a local variable in one execution and a
>>> shared variable in another! Or if the pointer is itself a shared
>>> variable and is dereferenced in another thread!)
>>
>> Good point! I did miss this complication. ;-)
>
> I suspect it wouldn't be so bad if herd7 disallowed taking addresses of
> local variables.
>
>

Herd7 does disallow taking addresses of local variables.

However, such tests can still be run on machine, provided function bodies are accepted by the C compiler.

—Luc