+ mm-page_alloc-fix-alignment-for-alloc_contig_pages_noprof.patch added to mm-new branch

+ mm-page_alloc-fix-alignment-for-alloc_contig_pages_noprof.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm/page_alloc: fix alignment for alloc_contig_pages_noprof()
has been added to the -mm mm-new branch.  Its filename is
     mm-page_alloc-fix-alignment-for-alloc_contig_pages_noprof.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-page_alloc-fix-alignment-for-alloc_contig_pages_noprof.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

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------------------------------------------------------
From: Wei Yang <richard.weiyang@gmail.com>
Subject: mm/page_alloc: fix alignment for alloc_contig_pages_noprof()
Date: Tue, 23 Sep 2025 00:19:43 +0000

Commit 5e27a2df03b8 ("mm/page_alloc: add alloc_contig_pages()") introduced
generic method for alloc_contig_pages().  But the alignment calculation
seems wrong.

Since ALIGN() only accepts power of two values, while nr_pages could be
any positive one, the result is not defined.

Use roundup() to calculate the correct alignment.

Link: https://lkml.kernel.org/r/20250923001943.2479-1-richard.weiyang@gmail.com
Fixes: 5e27a2df03b8 ("mm/page_alloc: add alloc_contig_pages()")
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_alloc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/page_alloc.c~mm-page_alloc-fix-alignment-for-alloc_contig_pages_noprof
+++ a/mm/page_alloc.c
@@ -7098,7 +7098,7 @@ struct page *alloc_contig_pages_noprof(u
 					gfp_zone(gfp_mask), nodemask) {
 		spin_lock_irqsave(&zone->lock, flags);
 
-		pfn = ALIGN(zone->zone_start_pfn, nr_pages);
+		pfn = roundup(zone->zone_start_pfn, nr_pages);
 		while (zone_spans_last_pfn(zone, pfn, nr_pages)) {
 			if (pfn_range_valid_contig(zone, pfn, nr_pages)) {
 				/*
_

Patches currently in -mm which might be from richard.weiyang@gmail.com are

mm-compaction-fix-low_pfn-advance-on-isolating-hugetlb.patch
mm-ksm-get-mm_slot-by-mm_slot_entry-when-slot-is-null.patch
mm-khugepaged-remove-definition-of-struct-khugepaged_mm_slot.patch
mm-khugepaged-remove-definition-of-struct-khugepaged_mm_slot-fix.patch
mm-khugepaged-use-start_addr-addr-for-better-reading.patch
mm-page_alloc-fix-alignment-for-alloc_contig_pages_noprof.patch