The patch titled
Subject: mm/mm_init.c: simplify logic of deferred_[init|free]_pages
has been added to the -mm mm-unstable branch. Its filename is
mm-mm_initc-simplify-logic-of-deferred__pages.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mm_initc-simplify-logic-of-deferred__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: Wei Yang <richard.weiyang@xxxxxxxxx>
Subject: mm/mm_init.c: simplify logic of deferred_[init|free]_pages
Date: Wed, 12 Jun 2024 02:04:21 +0000
Function deferred_[init|free]_pages are only used in
deferred_init_maxorder(), which makes sure the range to init/free is
within MAX_ORDER_NR_PAGES size.
With this knowledge, we can simplify these two functions. Since
* only the first pfn could be IS_MAX_ORDER_ALIGNED()
Also since the range passed to deferred_[init|free]_pages is always from
memblock.memory for those we have already allocated memmap to cover,
pfn_valid() always return true. Then we can remove related check.
Link: https://lkml.kernel.org/r/20240612020421.31975-1-richard.weiyang@xxxxxxxxx
Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mm_init.c | 63 ++++++-------------------------------------------
1 file changed, 8 insertions(+), 55 deletions(-)
--- a/mm/mm_init.c~mm-mm_initc-simplify-logic-of-deferred__pages
+++ a/mm/mm_init.c
@@ -1922,7 +1922,7 @@ unsigned long __init node_map_pfn_alignm
}
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
-static void __init deferred_free_range(unsigned long pfn,
+static void __init deferred_free_pages(unsigned long pfn,
unsigned long nr_pages)
{
struct page *page;
@@ -1962,68 +1962,21 @@ static inline void __init pgdat_init_rep
}
/*
- * Returns true if page needs to be initialized or freed to buddy allocator.
- *
- * We check if a current MAX_PAGE_ORDER block is valid by only checking the
- * validity of the head pfn.
- */
-static inline bool __init deferred_pfn_valid(unsigned long pfn)
-{
- if (IS_MAX_ORDER_ALIGNED(pfn) && !pfn_valid(pfn))
- return false;
- return true;
-}
-
-/*
- * Free pages to buddy allocator. Try to free aligned pages in
- * MAX_ORDER_NR_PAGES sizes.
- */
-static void __init deferred_free_pages(unsigned long pfn,
- unsigned long end_pfn)
-{
- unsigned long nr_free = 0;
-
- for (; pfn < end_pfn; pfn++) {
- if (!deferred_pfn_valid(pfn)) {
- deferred_free_range(pfn - nr_free, nr_free);
- nr_free = 0;
- } else if (IS_MAX_ORDER_ALIGNED(pfn)) {
- deferred_free_range(pfn - nr_free, nr_free);
- nr_free = 1;
- } else {
- nr_free++;
- }
- }
- /* Free the last block of pages to allocator */
- deferred_free_range(pfn - nr_free, nr_free);
-}
-
-/*
* Initialize struct pages. We minimize pfn page lookups and scheduler checks
* by performing it only once every MAX_ORDER_NR_PAGES.
* Return number of pages initialized.
*/
-static unsigned long __init deferred_init_pages(struct zone *zone,
- unsigned long pfn,
- unsigned long end_pfn)
+static unsigned long __init deferred_init_pages(struct zone *zone,
+ unsigned long pfn,
+ unsigned long end_pfn)
{
int nid = zone_to_nid(zone);
- unsigned long nr_pages = 0;
+ unsigned long nr_pages = end_pfn - pfn;
int zid = zone_idx(zone);
- struct page *page = NULL;
+ struct page *page = pfn_to_page(pfn);
- for (; pfn < end_pfn; pfn++) {
- if (!deferred_pfn_valid(pfn)) {
- page = NULL;
- continue;
- } else if (!page || IS_MAX_ORDER_ALIGNED(pfn)) {
- page = pfn_to_page(pfn);
- } else {
- page++;
- }
+ for (; pfn < end_pfn; pfn++, page++)
__init_single_page(page, pfn, zid, nid);
- nr_pages++;
- }
return nr_pages;
}
@@ -2102,7 +2055,7 @@ deferred_init_maxorder(u64 *i, struct zo
break;
t = min(mo_pfn, epfn);
- deferred_free_pages(spfn, t);
+ deferred_free_pages(spfn, t - spfn);
if (mo_pfn <= epfn)
break;
_
Patches currently in -mm which might be from richard.weiyang@xxxxxxxxx are
mm-mm_initc-print-mem_init-info-after-defer_init-is-done.patch
mm-mm_initc-simplify-logic-of-deferred__pages.patch
