On 25.08.25 16:32, Mike Rapoport wrote:
On Mon, Aug 25, 2025 at 02:48:58PM +0200, David Hildenbrand wrote:
On 23.08.25 10:59, Mike Rapoport wrote:
On Fri, Aug 22, 2025 at 08:24:31AM +0200, David Hildenbrand wrote:
On 22.08.25 06:09, Mika Penttilä wrote:
On 8/21/25 23:06, David Hildenbrand wrote:
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.
We can surely update the docs, but unfortunately I don't see how to avoid
hacking around it in hugetlb.
Since it's used to optimise HVO even further to the point hugetlb open
codes memmap initialization, I think it's fair that it should deal with all
possible configurations.
Remind me, why can't we support memblock_reserved_mark_noinit() when
CONFIG_DEFERRED_STRUCT_PAGE_INIT is disabled?
--
Cheers
David / dhildenb
