On Tue, Feb 02, 2021 at 02:29:11PM +0100, David Hildenbrand wrote:
> > @@ -1088,10 +1150,10 @@ remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
> > pages++;
> > } else {
> > /* If here, we are freeing vmemmap pages. */
> > - memset((void *)addr, PAGE_INUSE, next - addr);
> > + memset((void *)addr, PAGE_UNUSED, next - addr);
> > page_addr = page_address(pud_page(*pud));
> > - if (!memchr_inv(page_addr, PAGE_INUSE,
> > + if (!memchr_inv(page_addr, PAGE_UNUSED,
> > PUD_SIZE)) {
> > free_pagetable(pud_page(*pud),
> > get_order(PUD_SIZE));
>
> I'm sorry to bother you again, but isn't that dead code as well?
Heh, I spotted that earlier, but I did not think much of it honestly.
All this was introduced by:
commit ae9aae9eda2db71bf4b592f15618b0160eb07731
Author: Wen Congyang <wency@xxxxxxxxxxxxxx>
Date: Fri Feb 22 16:33:04 2013 -0800
memory-hotplug: common APIs to support page tables hot-remove
> How do we ever end up using 1GB pages for the vmemmap? At least not via
> vmemmap_populate() - so I guess never? There are not many occurrences of
> "PUD_SIZE" in the file after all ...
AFAICT, we don't. The largest we populate for vmemmap is 2MB.
I see init_memory_mapping can use 1G, but that should not affect us.
I guess that the vmemmap handling for 1GB can go as well.
I will update the patchset.
--
Oscar Salvador
SUSE L3
