The patch titled
Subject: mm/page_ext: init page_ext early if there are no deferred struct pages
has been added to the -mm mm-unstable branch. Its filename is
mm-page_ext-init-page_ext-early-if-there-are-no-deferred-struct-pages.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-page_ext-init-page_ext-early-if-there-are-no-deferred-struct-pages.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
Subject: mm/page_ext: init page_ext early if there are no deferred struct pages
Date: Tue, 17 Jan 2023 20:46:17 +0000
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.
Link: https://lkml.kernel.org/r/20230117204617.1553748-1-pasha.tatashin@xxxxxxxxxx
Signed-off-by: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Charan Teja Kalla <quic_charante@xxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Li Zhe <lizhe.67@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/include/linux/page_ext.h~mm-page_ext-init-page_ext-early-if-there-are-no-deferred-struct-pages
+++ a/include/linux/page_ext.h
@@ -55,6 +55,7 @@ struct page_ext {
unsigned long flags;
};
+extern bool deferred_struct_pages;
extern bool early_page_ext;
extern unsigned long page_ext_size;
extern void pgdat_page_ext_init(struct pglist_data *pgdat);
--- a/init/main.c~mm-page_ext-init-page_ext-early-if-there-are-no-deferred-struct-pages
+++ a/init/main.c
@@ -855,8 +855,8 @@ static void __init mm_init(void)
pgtable_init();
debug_objects_mem_init();
vmalloc_init();
- /* Should be run after vmap initialization */
- if (early_page_ext_enabled())
+ /* If no deferred init page_ext now, as vmap is fully initialized */
+ if (!deferred_struct_pages)
page_ext_init();
/* Should be run before the first non-init thread is created */
init_espfix_bsp();
@@ -1628,7 +1628,7 @@ static noinline void __init kernel_init_
padata_init();
page_alloc_init_late();
/* Initialize page ext after all struct pages are initialized. */
- if (!early_page_ext_enabled())
+ if (deferred_struct_pages)
page_ext_init();
do_basic_setup();
--- a/mm/page_alloc.c~mm-page_ext-init-page_ext-early-if-there-are-no-deferred-struct-pages
+++ a/mm/page_alloc.c
@@ -430,6 +430,8 @@ EXPORT_SYMBOL(nr_online_nodes);
int page_group_by_mobility_disabled __read_mostly;
+bool deferred_struct_pages __meminitdata;
+
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
/*
* During boot we initialize deferred pages on-demand, as needed, but once
@@ -6803,8 +6805,10 @@ void __meminit memmap_init_range(unsigne
if (context == MEMINIT_EARLY) {
if (overlap_memmap_init(zone, &pfn))
continue;
- if (defer_init(nid, pfn, zone_end_pfn))
+ if (defer_init(nid, pfn, zone_end_pfn)) {
+ deferred_struct_pages = true;
break;
+ }
}
page = pfn_to_page(pfn);
--- a/mm/page_ext.c~mm-page_ext-init-page_ext-early-if-there-are-no-deferred-struct-pages
+++ a/mm/page_ext.c
@@ -92,7 +92,7 @@ unsigned long page_ext_size;
static unsigned long total_usage;
static struct page_ext *lookup_page_ext(const struct page *page);
-bool early_page_ext;
+bool early_page_ext __meminitdata;
static int __init setup_early_page_ext(char *str)
{
early_page_ext = true;
_
Patches currently in -mm which might be from pasha.tatashin@xxxxxxxxxx are
mm-page_ext-do-not-allocate-space-for-page_ext-flags-if-not-needed.patch
mm-page_ext-init-page_ext-early-if-there-are-no-deferred-struct-pages.patch
