Re: staging: lustre: One function call less in class_register_type() after error detection

Oleg Drokin
2016-07-26T21:49:49Z

On Jul 26, 2016, at 3:56 PM, SF Markus Elfring wrote:

>> But kobject_put() already checks for NULL, right?
>
> Yes. - Such an input parameter validation is performed by the
> function implementation.
>
>
>> you just submitted another batch about that in other area.
>
> I sent update suggestions because of this function property for two
> Linux software modules in the year 2015.
>
>
>>> Adjust jump targets according to the Linux coding style convention.
>>
>> Not that I am totally against this patch,
>
> Thanks for your feedback.
>
>
>> but when we do not need the extra checks, a single jump target is ok too in my mind
>
> A single goto label will look convenient for a while. It will often work
> for several use cases.
>
>
>> (extra benefit - there's not going to be any chance of a mistake to where to jump to).
>
> I have got an other opinion when you would like to care for a bit
> more software efficiency.
>
>
>> And when we have a single jump target, there's no supersmart naming
>> like free_this_and_that_and_that_other_thing_too.
>
> How often do you care for efficient exception handling in the shown
> function implementations?

This function is called several times during lustre module insert.
Namely it's called 5 times for 5 types:
osc, mdc, lov, lmv, mgc.

It's not called any more than that, so it's not exactly a super hot-path function
to overoptimize it, and the failure is presumed to never happen too
(or the module would be non-functional).

I guess you have already did all the work so I don't have any principal objections
here, it's just like I said, in a non-super contended path, a single
"fail" label is probably easier on the developer when they need to add another
check there, as opposed to figuring and possibly adding a correct another
label that would do something sensible.

Thank you for your contributions.