[PATCH v8 2/8] nptl: Add C11 threads mtx_* functions

[Florian Weimer]

On 07/13/2018 03:08 PM, Adhemerval Zanella wrote:
> 
> 
> On 12/07/2018 17:38, Florian Weimer wrote:
>> On 07/12/2018 10:30 PM, Adhemerval Zanella wrote:
>>
>>>> I'm concerned about this because in the future, we might compile the implementations to remove checks that are not needed for the C11 implementations.
>>>
>>> Why kind of scenario do you have in mind? Maybe use a more streamlined
>>> internal implementation for C11 threads?
>>
>> Yes, the polymorphic mutex types must have *some* overhead (think of speculatively executing the wrong atomics), and less polymorphism should improve performance.
> 
> I think it would quite feasible in next releases to refactor the mutex
> code into C11 required operation and POSIX one and optimize C11
> implementation with a simpler internal one. The bulk of the work is
> disentangle the mutex code (I started to check on this sometime ago,
> but got sidetracked).

Sure, we can delay this work somewhat, but I'd like to backport the 
optimization into 2.28 once we have it, to discourage such invalid uses.

Thanks,
Florian