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Re: [PATCH v2] Add malloc micro benchmark
On 05/01/2018 12:32, Carlos O'Donell wrote:
> On 01/04/2018 05:48 AM, Wilco Dijkstra wrote:
>> Carlos O'Donell wrote:
>>>
>>> Don't use mallopt, please make it a tunable then.
>>>
>>> The mallopt API already had 2 secret arena options which eventually became
>>> so well used they were baked into the API and had to be made public.
>>
>> Unfortunately tunables are not exported so you can't use them outside of GLIBC:
>>
>> /build/glibc/benchtests/bench-malloc-simple.o: In function `bench':
>> bench-malloc-simple.c:(.text+0x19c): undefined reference to `__tunable_set_val'
>> collect2: error: ld returned 1 exit status
>
> Correct, we only have a env-var frontend right now, and the internal API is not
> made accessible via GLIBC_PRIVATE.
>
> You have 3 options for tests:
>
> * Use the env vars to adjust test behaviour. Run the tests multiple times.
> * Add a new C API frontend, very valuable, but more time consuming.
> * Expose the existing internal C API via GLIBC_PRIVATE for testing, and throw
> it away later when we get a proper C API frontend.
>
Do we want a C API to tied the malloc implementation to some tunables? My
understanding is the tunable api idea is not really enforce retro-compability
(where a C api would enforce it).