Re: drivers: Inline code in devm_platform_ioremap_resource() from two functions

[Markus Elfring]

>> Would you like to check the software circumstances once more
>> for the generation of a similar code structure by a C compiler
>> (or optimiser)?
>
> As said: unfortunately, I don't have the time to do that

I became curious if you would like to adjust your software development
attention a bit more also in this area.


> - you'd have to tell us, what exactly you've got in mind.

I try to point possibilities out to improve the combination of
two functions.


> If it's just about some error checks which happen to be redundant in a
> particular case, you'll have to show that this case is a *really* hot
> path (eg. irq, syscall, scheduling, etc) - but I don't see that here.

1. May the check âresource_type(res) == IORESOURCE_MEMâ be performed
   in a local loop?

2. How hot do you find the null pointer check for the device
   input parameter of the function âdevm_ioremap_resourceâ?


> Any actual measurements on how your patch improves that ?

Not yet. - Which benchmarks would you trust here?


> Look, I understand that you'd like to squeeze out maximum performance,

I hope so.


> but this has to be practically maintainable.

This can be achieved if more contributors would find proposed
adjustments helpful for another software transformation.

Regards,
Markus