[to-be-updated] mm-shmem-disallow-hugepages-if-the-system-wide-shmem-thp-sysfs-settings-are-disabled.patch removed from -mm tree

[to-be-updated] mm-shmem-disallow-hugepages-if-the-system-wide-shmem-thp-sysfs-settings-are-disabled.patch removed from -mm tree

[Andrew Morton]

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The quilt patch titled
     Subject: mm: shmem: disallow hugepages if the system-wide shmem THP sysfs settings are disabled
has been removed from the -mm tree.  Its filename was
     mm-shmem-disallow-hugepages-if-the-system-wide-shmem-thp-sysfs-settings-are-disabled.patch

This patch was dropped because an updated version will be issued

------------------------------------------------------
From: Baolin Wang <baolin.wang@linux.alibaba.com>
Subject: mm: shmem: disallow hugepages if the system-wide shmem THP sysfs settings are disabled
Date: Thu, 5 Jun 2025 16:00:59 +0800

MADV_COLLAPSE will ignore the system-wide shmem THP sysfs settings, which
means that even though we have disabled the shmem THP configuration,
MADV_COLLAPSE will still attempt to collapse into a shmem THP.  This
violates the rule we have agreed upon: never means never.

Another rule for madvise, referring to David's suggestion: “allowing for
collapsing in a VM without VM_HUGEPAGE in the "madvise" mode would be
fine".

Then the current strategy is:

For shmem, if none of always, madvise, within_size, and inherit have
enabled PMD-sized THP, then MADV_COLLAPSE will be prohibited from
collapsing PMD-sized THP.

For tmpfs, if the mount option is set with the 'huge=never' parameter,
then MADV_COLLAPSE will be prohibited from collapsing PMD-sized THP.

Link: https://lkml.kernel.org/r/39d7617a6142c6091f233357171c5793e0992d36.1749109709.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/huge_memory.c |    2 +-
 mm/shmem.c       |    6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

--- a/mm/huge_memory.c~mm-shmem-disallow-hugepages-if-the-system-wide-shmem-thp-sysfs-settings-are-disabled
+++ a/mm/huge_memory.c
@@ -166,7 +166,7 @@ unsigned long __thp_vma_allowable_orders
 	 * own flags.
 	 */
 	if (!in_pf && shmem_file(vma->vm_file))
-		return shmem_allowable_huge_orders(file_inode(vma->vm_file),
+		return orders & shmem_allowable_huge_orders(file_inode(vma->vm_file),
 						   vma, vma->vm_pgoff, 0,
 						   !enforce_sysfs);
 
--- a/mm/shmem.c~mm-shmem-disallow-hugepages-if-the-system-wide-shmem-thp-sysfs-settings-are-disabled
+++ a/mm/shmem.c
@@ -625,7 +625,7 @@ static unsigned int shmem_huge_global_en
 		return 0;
 	if (shmem_huge == SHMEM_HUGE_DENY)
 		return 0;
-	if (shmem_huge_force || shmem_huge == SHMEM_HUGE_FORCE)
+	if (shmem_huge == SHMEM_HUGE_FORCE)
 		return maybe_pmd_order;
 
 	/*
@@ -660,7 +660,7 @@ static unsigned int shmem_huge_global_en
 
 		fallthrough;
 	case SHMEM_HUGE_ADVISE:
-		if (vm_flags & VM_HUGEPAGE)
+		if (shmem_huge_force || (vm_flags & VM_HUGEPAGE))
 			return maybe_pmd_order;
 		fallthrough;
 	default:
@@ -1783,7 +1783,7 @@ unsigned long shmem_allowable_huge_order
 	/* Allow mTHP that will be fully within i_size. */
 	mask |= shmem_get_orders_within_size(inode, within_size_orders, index, 0);
 
-	if (vm_flags & VM_HUGEPAGE)
+	if (shmem_huge_force || (vm_flags & VM_HUGEPAGE))
 		mask |= READ_ONCE(huge_shmem_orders_madvise);
 
 	if (global_orders > 0)
_

Patches currently in -mm which might be from baolin.wang@linux.alibaba.com are

mm-fix-the-inaccurate-memory-statistics-issue-for-users.patch