+ mm-huge_memory-fix-a-folio_split-race-condition-with-folio_try_get-fix.patch added to mm-hotfixes-unstable branch

+ mm-huge_memory-fix-a-folio_split-race-condition-with-folio_try_get-fix.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm-huge_memory-fix-a-folio_split-race-condition-with-folio_try_get-fix
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     mm-huge_memory-fix-a-folio_split-race-condition-with-folio_try_get-fix.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-huge_memory-fix-a-folio_split-race-condition-with-folio_try_get-fix.patch

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

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------------------------------------------------------
From: Zi Yan <ziy@nvidia.com>
Subject: mm-huge_memory-fix-a-folio_split-race-condition-with-folio_try_get-fix
Date: Tue, 3 Mar 2026 11:26:41 -0500

move comment, per David

Link: https://lkml.kernel.org/r/5C9FA053-A4C6-4615-BE05-74E47A6462B3@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: David Hildenbrand <david@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/huge_memory.c |   10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

--- a/mm/huge_memory.c~mm-huge_memory-fix-a-folio_split-race-condition-with-folio_try_get-fix
+++ a/mm/huge_memory.c
@@ -3656,17 +3656,15 @@ static int __split_unmapped_folio(struct
 			 * uniform split has xas_split_alloc() called before
 			 * irq is disabled to allocate enough memory, whereas
 			 * non-uniform split can handle ENOMEM.
+			 * Use the to-be-split folio, so that a parallel
+			 * folio_try_get() waits on it until xarray is updated
+			 * with after-split folios and the original one is
+			 * unfrozen.
 			 */
 			if (split_type == SPLIT_TYPE_UNIFORM) {
 				xas_split(xas, old_folio, old_order);
 			} else {
 				xas_set_order(xas, folio->index, split_order);
-				/*
-				 * use the to-be-split folio, so that a parallel
-				 * folio_try_get() waits on it until xarray is
-				 * updated with after-split folios and
-				 * the original one is unfrozen.
-				 */
 				xas_try_split(xas, old_folio, old_order);
 				if (xas_error(xas))
 					return xas_error(xas);
_

Patches currently in -mm which might be from ziy@nvidia.com are

mm-cma-move-put_page_testzero-out-of-vm_warn_on-in-cma_release.patch
mm-huge_memory-fix-a-folio_split-race-condition-with-folio_try_get.patch
mm-huge_memory-fix-a-folio_split-race-condition-with-folio_try_get-fix.patch