Re: [PATCH v2 0/7] Implement inline static calls on PPC32 - v2

From: Christophe Leroy
Date: Thu Sep 08 2022 - 02:12:04 EST




Le 08/09/2022 à 02:13, Benjamin Gray a écrit :
> On Thu, 2022-09-01 at 16:46 +0000, Christophe Leroy wrote:
>> Surprisingly, I get worst performance with inline static call than
>> with
>> out of line static call:
>
> I'm not sure what hackbench is doing, but when microbenchmarking 64 bit
> out-of-line calls in a loop I saw a similar thing where adding more
> indirection improved the performance despite doing more work. The cause
> seemed to be a combination of using older hardware and the target being
> too short (just an integer increment). Moving to a newer machine and
> adding a lot of NOPs to the target made the performance make sense.

Yes might be.

I think I'll first do new tests with CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B

Christophe