All those reasons should be a part of the changelog.
....
I am not sure these are sufficient justifications but that is something
to discuss. And hence it should be a part of the changelog.

OK, These reasons will be added to the patch notesin later versions.

quoted

3. In the case where the user does not need vmpressure,  vmpressure
calculation is additional overhead.

You should quantify that and argue why that overhead cannot be further
reduced without config/boot time knobs.

The test results of the previously used PFT tool may not be obvious.
Is there a better way to quantify it?

quoted

In some special scenes with tight memory, vmpressure will be executed
frequently.we use "likely" and "inline"
to improve the performance of the kernel, why not reduce some
unnecessary calculations?

I am all for improving the code. Is it possible to do it by other means?
E.g. reduce a potential overhead when there no events registered?

Yes, the method you mentioned may be feasible, but it does not conflict
with this patch.

Thanks.