Convert vm_page_alloc() callers to use vm_page_alloc_noobj().

[markj]

Summary

Remove page zeroing code from consumers and stop specifying
VM_ALLOC_NOOBJ. In a few places I also converted an allocation loop to
use VM_ALLOC_WAITOK.

Similarly, convert vm_page_alloc_domain() callers.

Note that callers are now responsible for assigning the pindex.

[kib]

sys/i386/i386/pmap.c

2086–2087

Eliminate m while there?

[• hselasky]

Looks good from my point of view.

[markj]

Eliminate a local var in the i386 pmap.

[markj]

Drop unused VM_ALLOC_NOBUSY from consumers.

[alc]

sys/amd64/amd64/pmap.c

11404–11406

This doesn't look right.

[markj]

Fix a couple of callers that weren't converted properly.

[markj]

Tinderbox fixes.

[alc]

There are a number of places where VM_ALLOC_NORMAL is missing, but implied. And, given its definition (as 0), we have no way of enforcing its use. So, I'm ready to suggest that we simply eliminate it.

[markj]

Drop uses of VM_ALLOC_NORMAL from vm_page_alloc_noobj() and
vm_page_alloc_noobj_domain() callers.

[alc]

sys/amd64/amd64/pmap.c

4354

As an aside, this comment should explain why 'pmap' isn't passed to 'pmap_alloc_pt_page'.

4386–4387

As an aside, as above this deserves a comment (as part of a separate patch) so that readers don't think it is an accounting bug.

4391

I feel like I'm missing something here. We only appear to initialize one PTE within the pml5 page and the contents of the rest of the PTEs within the page are unknown.

sys/dev/xen/balloon/balloon.c

237

As an aside, it's curious that we specify "nodump" in the virtio driver but not here.

[markj]

sys/amd64/amd64/pmap.c

4354

Is it only because the pmap stats fields are not initialized at this point? If so, I wonder if we should instead initialize them first and count this page (with corresponding changes to pmap_release()).

4386–4387

Here it makes a bit more sense that the page isn't counted.

4391

I think this is a bug.

sys/dev/xen/balloon/balloon.c

237

I can't see a reason for virtio to specify NODUMP: it doesn't call dump_add_page() and I can't see how or why virtio balloon pages would ever be mapped.

[kib]

sys/amd64/amd64/pmap.c

4386–4387

I do not see why, it is reasonable to account for all page table pages, even if we have two page tables.

4391

Yes it is bug. Would you add VM_ALLOC_ZERO as part of this patch or should we do a separate patch?

[markj]

sys/amd64/amd64/pmap.c

4386–4387

Ah, pmap_resident_count_adj() asserts that the pmap mutex is held, but at this point it is not. And it doesn't seem very useful to manually adjust the count.

[alc]

sys/amd64/amd64/pmap.c

4354

No. Think about the early termination optimization in pmap_remove(). For it to work, the root-level PTPs allocated in this function can't be counted in the pmap's resident.

[alc]

sys/dev/xen/balloon/balloon.c

237

Yes, you are right. There is no reason for the virtio balloon driver to pass the "no dump" flag.