vm_radix: Add iter lookup_le interface

[alc]

I'm looking at patches from both you and @dougm that define this function. However, each of you adds it in a different location within the file. :-)

There doesn't seem to be any rhyme or reason to the order of the function definitions. Could we please decide on one, and add this function accordingly?

[alc]

To be clear, there is no question that this function will get used, so adding it sooner, rather than later, would be okay with me.

[bnovkov]

In D47046#1078597, @alc wrote:

I'm looking at patches from both you and @dougm that define this function. However, each of you adds it in a different location within the file. :-)

There doesn't seem to be any rhyme or reason to the order of the function definitions. Could we please decide on one, and add this function accordingly?

I don't have a preference, I'm fine with anything as long as the function gets defined :)

[dougm]

In D47036, I put it after vm_radix_iter_step, mostly because PCTRIE_ITER_LOOKUP_LE comes shortly after PCTRIE_ITER_STEP_GE in pctrie.h. 'step' and 'jump' are built on top of lookup_ge, so I kept them grouped with lookup_ge.

I had a comment, and there should be one here for consistency with all the other little functions in this file.

I agree that we should have a sensible order to things, and that we don't. I suggest non-iter before iter, then insert before lookup before remove before replace before disposal, then lookup == before lookup >= before lookup <=.

[alc]

In D47046#1079047, @dougm wrote:

In D47036, I put it after vm_radix_iter_step, mostly because PCTRIE_ITER_LOOKUP_LE comes shortly after PCTRIE_ITER_STEP_GE in pctrie.h. 'step' and 'jump' are built on top of lookup_ge, so I kept them grouped with lookup_ge.

I had a comment, and there should be one here for consistency with all the other little functions in this file.

I agree that we should have a sensible order to things, and that we don't. I suggest non-iter before iter, then insert before lookup before remove before replace before disposal, then lookup == before lookup >= before lookup <=.

I'm fine with this ordering. Please commit this function in a place consistent with this ordering. Consider the commit reviewed. We can rearrange the rest of the functions later.