[merged mm-stable] mm-mm_init-use-for_each_valid_pfn-in-init_unavailable_range.patch removed from -mm tree

[merged mm-stable] mm-mm_init-use-for_each_valid_pfn-in-init_unavailable_range.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/mm_init: use for_each_valid_pfn() in init_unavailable_range()
has been removed from the -mm tree.  Its filename was
     mm-mm_init-use-for_each_valid_pfn-in-init_unavailable_range.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: David Woodhouse <dwmw@amazon.co.uk>
Subject: mm/mm_init: use for_each_valid_pfn() in init_unavailable_range()
Date: Wed, 23 Apr 2025 14:33:43 +0100

Currently, memmap_init initializes pfn_hole with 0 instead of
ARCH_PFN_OFFSET. Then init_unavailable_range will start iterating each
page from the page at address zero to the first available page, but it
won't do anything for pages below ARCH_PFN_OFFSET because pfn_valid
won't pass.

If ARCH_PFN_OFFSET is very large (e.g., something like 2^64-2GiB if the
kernel is used as a library and loaded at a very high address), the
pointless iteration for pages below ARCH_PFN_OFFSET will take a very long
time, and the kernel will look stuck at boot time.

Use for_each_valid_pfn() to skip the pointless iterations.

Link: https://lkml.kernel.org/r/20250423133821.789413-8-dwmw2@infradead.org
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reported-by: Ruihan Li <lrh2000@pku.edu.cn>
Suggested-by: Mike Rapoport <rppt@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Tested-by: Ruihan Li <lrh2000@pku.edu.cn>
Tested-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/mm_init.c |    6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

--- a/mm/mm_init.c~mm-mm_init-use-for_each_valid_pfn-in-init_unavailable_range
+++ a/mm/mm_init.c
@@ -851,11 +851,7 @@ static void __init init_unavailable_rang
 	unsigned long pfn;
 	u64 pgcnt = 0;
 
-	for (pfn = spfn; pfn < epfn; pfn++) {
-		if (!pfn_valid(pageblock_start_pfn(pfn))) {
-			pfn = pageblock_end_pfn(pfn) - 1;
-			continue;
-		}
+	for_each_valid_pfn(pfn, spfn, epfn) {
 		__init_single_page(pfn_to_page(pfn), pfn, zone, node);
 		__SetPageReserved(pfn_to_page(pfn));
 		pgcnt++;
_

Patches currently in -mm which might be from dwmw@amazon.co.uk are