7ec7096b85
page_ext must be initialized after all struct pages are initialized. Therefore, page_ext is initialized after page_alloc_init_late(), and can optionally be initialized earlier via early_page_ext kernel parameter which as a side effect also disables deferred struct pages. Allow to automatically init page_ext early when there are no deferred struct pages in order to be able to use page_ext during kernel boot and track for example page allocations early. [pasha.tatashin@soleen.com: fix build with CONFIG_PAGE_EXTENSION=n] Link: https://lkml.kernel.org/r/20230118155251.2522985-1-pasha.tatashin@soleen.com Link: https://lkml.kernel.org/r/20230117204617.1553748-1-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Charan Teja Kalla <quic_charante@quicinc.com> Cc: David Hildenbrand <david@redhat.com> Cc: Li Zhe <lizhe.67@bytedance.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>