I believe this deserves much more detailed explanation why this is safe. What actually prevents any pfn walker from seeing an uninitialized struct page? Please make your assumptions explicit in the commit log so that we can check them independently.
There is nothing prevents pfn walkers from walk over any struct pages deferred and non-deferred. However, during boot before deferred pages are initialized we have just a few places that do that, and all of those cases are fixed in this patchset.
Also this is done with some purpose which is the perfmance, right? You have mentioned that in the cover letter but if somebody is going to read through git logs this wouldn't be obvious from the specific commit. So add that information here as well. Especially numbers will be interesting.
I will add more performance data to this patch comment. -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
