Hi Souptick, On Fri, Oct 5, 2018 at 12:01 PM Souptick Joarder <jrdr.linux@xxxxxxxxx> wrote: > > The final goal is to remove vm_insert_page by converting it to > vmf_insert_page. But to do that we have to first introduce the > new API which is similar to vm_insert_page (for non #PF). I tried this by > introducing vm_insert_kmem_page ( * identical as vm_insert_page > except API name *) in this patch. But this looks like a bad approach. We are going in circles here. That you want to convert vm_insert_page to vmf_insert_page for the PF case is fine and understood. However, you don't *need* to introduce a new name for the remaining non-PF cases if the function is going to be the exact same thing as before. You say "The final goal is to remove vm_insert_page", but you haven't justified *why* you need to remove that name. Now, if we want to rename the function for some reason (e.g. avoid confusion with vmf_insert_page), that is fine but is another topic. It may be or not a good idea, but it is orthogonal to the vmf_ work. Matthew, on this regard, told you that you shouldn't duplicate functions. If you want a rename, do so; but don't copy the code. In other words: nobody said introducing the vm_insert_kmem_page name is a bad idea -- what Matthew told you is that *duplicating* vm_insert_page just for that is bad. Further, you are copying the code (if I understand your thought process) because you want to change the callers of non-PF first, and then do the "full conversion from vm_* to vmf_*". However, that is confusing, because there is no need to change non-PF callers of vm_insert_page since they don't care about the new vmf_* functions. Instead, the proper way of doing this is: 1. Introduce the vmf_* API 2. Change all PF-users users to that (leaving all non-PF ones untouched!) -- if this is too big, you can split this patch into several patches, one per subsystem, etc. 3. Remove the vm_* functions (except the ones that are still used in non-PF contexts, e.g. vm_insert_page) Then, optionally, if you want to rename the function for the remaining non-PF users: 4. Rename vm_insert_page (justifying why the current name is confusing *on its own merits*). Otherwise, if you want to pursue Matthew's idea: 4. Introduce the vm_insert_range (possibly leveraging vm_insert_page, or not; you have to see what is best). 5. Replace those callers that can take advantage of vm_insert_range 6. Remove vm_insert_page and replace callers with vm_insert_range (only if it is not worth to keep vm_insert_range, again justifying it *on its own merits*) As you see, these are all logical step-by-step improvements, without duplicating functions temporarily, leaving temporary changes or changing current callers to new APIs for unrelated reasons (i.e. no need to introduce vm_insert_kmem_page simply to do a "conversion" to vmf_). Cheers, Miguel
