On 23.08.25 10:59, Mike Rapoport wrote:

On Fri, Aug 22, 2025 at 08:24:31AM +0200, David Hildenbrand wrote:

quoted

On 22.08.25 06:09, Mika Penttilä wrote:

quoted

On 8/21/25 23:06, David Hildenbrand wrote:

quoted

All pages were already initialized and set to PageReserved() with a
refcount of 1 by MM init code.

Just to be sure, how is this working with MEMBLOCK_RSRV_NOINIT, where MM is supposed not to
initialize struct pages?

Excellent point, I did not know about that one.

Spotting that we don't do the same for the head page made me assume that
it's just a misuse of __init_single_page().

But the nasty thing is that we use memblock_reserved_mark_noinit() to only
mark the tail pages ...

And even nastier thing is that when CONFIG_DEFERRED_STRUCT_PAGE_INIT is
disabled struct pages are initialized regardless of
memblock_reserved_mark_noinit().

I think this patch should go in before your updates:

Shouldn't we fix this in memblock code?

Hacking around that in the memblock_reserved_mark_noinit() user sound 
wrong -- and nothing in the doc of memblock_reserved_mark_noinit() 
spells that behavior out.

-- 
Cheers

David / dhildenb