From de57807e6f267a658a046dbca44dc40fe806d60f Mon Sep 17 00:00:00 2001
From: "Mike Rapoport (IBM)" <rppt@kernel.org>
Date: Tue, 21 Mar 2023 19:05:09 +0200
Subject: [PATCH] init,mm: fold late call to page_ext_init() to
 page_alloc_init_late()

When deferred initialization of struct pages is enabled, page_ext_init()
must be called after all the deferred initialization is done, but there is
no point to keep it a separate call from kernel_init_freeable() right
after page_alloc_init_late().

Fold the call to page_ext_init() into page_alloc_init_late() and localize
deferred_struct_pages variable.

Link: https://lkml.kernel.org/r/20230321170513.2401534-11-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 include/linux/page_ext.h | 2 --
 init/main.c              | 4 ----
 mm/mm_init.c             | 6 +++++-
 3 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/include/linux/page_ext.h b/include/linux/page_ext.h
index bc2e39090a1f..67314f648aeb 100644
--- a/include/linux/page_ext.h
+++ b/include/linux/page_ext.h
@@ -29,8 +29,6 @@ struct page_ext_operations {
 	bool need_shared_flags;
 };
 
-extern bool deferred_struct_pages;
-
 #ifdef CONFIG_PAGE_EXTENSION
 
 /*
diff --git a/init/main.c b/init/main.c
index f1b2d8d80987..43bc4c82dc58 100644
--- a/init/main.c
+++ b/init/main.c
@@ -62,7 +62,6 @@
 #include <linux/rmap.h>
 #include <linux/mempolicy.h>
 #include <linux/key.h>
-#include <linux/page_ext.h>
 #include <linux/debug_locks.h>
 #include <linux/debugobjects.h>
 #include <linux/lockdep.h>
@@ -1565,9 +1564,6 @@ static noinline void __init kernel_init_freeable(void)
 
 	padata_init();
 	page_alloc_init_late();
-	/* Initialize page ext after all struct pages are initialized. */
-	if (deferred_struct_pages)
-		page_ext_init();
 
 	do_basic_setup();
 
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 43f6d3ed24ef..ff70da11e797 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -225,7 +225,7 @@ static unsigned long nr_kernel_pages __initdata;
 static unsigned long nr_all_pages __initdata;
 static unsigned long dma_reserve __initdata;
 
-bool deferred_struct_pages __meminitdata;
+static bool deferred_struct_pages __meminitdata;
 
 static DEFINE_PER_CPU(struct per_cpu_nodestat, boot_nodestats);
 
@@ -2358,6 +2358,10 @@ void __init page_alloc_init_late(void)
 
 	for_each_populated_zone(zone)
 		set_zone_contiguous(zone);
+
+	/* Initialize page ext after all struct pages are initialized. */
+	if (deferred_struct_pages)
+		page_ext_init();
 }
 
 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
-- 
2.11.0