+ khugepaged-kick-khugepaged-for-enabling-none-pmd-sized-mthps.patch added to mm-new branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: khugepaged: kick khugepaged for enabling none-PMD-sized mTHPs
has been added to the -mm mm-new branch.  Its filename is
     khugepaged-kick-khugepaged-for-enabling-none-pmd-sized-mthps.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/khugepaged-kick-khugepaged-for-enabling-none-pmd-sized-mthps.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
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Baolin Wang <baolin.wang@linux.alibaba.com>
Subject: khugepaged: kick khugepaged for enabling none-PMD-sized mTHPs
Date: Tue, 1 Jul 2025 23:57:39 -0600

When only non-PMD-sized mTHP is enabled (such as only 64K mTHP enabled),
we should also allow kicking khugepaged to attempt scanning and collapsing
64K mTHP.  Modify hugepage_pmd_enabled() to support mTHP collapse, and
while we are at it, rename it to make the function name more clear.

Link: https://lkml.kernel.org/r/20250702055742.102808-13-npache@redhat.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Nico Pache <npache@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter (Ampere) <cl@gentwo.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rafael Aquini <raquini@redhat.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Reported-by:Takashi Iwai <tiwai@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Hellstrom <thomas.hellstrom@linux.intel.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zach O'Keefe <zokeefe@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/khugepaged.c |   20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

--- a/mm/khugepaged.c~khugepaged-kick-khugepaged-for-enabling-none-pmd-sized-mthps
+++ a/mm/khugepaged.c
@@ -430,7 +430,7 @@ static inline int khugepaged_test_exit_o
 	       test_bit(MMF_DISABLE_THP, &mm->flags);
 }
 
-static bool hugepage_pmd_enabled(void)
+static bool hugepage_enabled(void)
 {
 	/*
 	 * We cover the anon, shmem and the file-backed case here; file-backed
@@ -442,11 +442,11 @@ static bool hugepage_pmd_enabled(void)
 	if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) &&
 	    hugepage_global_enabled())
 		return true;
-	if (test_bit(PMD_ORDER, &huge_anon_orders_always))
+	if (READ_ONCE(huge_anon_orders_always))
 		return true;
-	if (test_bit(PMD_ORDER, &huge_anon_orders_madvise))
+	if (READ_ONCE(huge_anon_orders_madvise))
 		return true;
-	if (test_bit(PMD_ORDER, &huge_anon_orders_inherit) &&
+	if (READ_ONCE(huge_anon_orders_inherit) &&
 	    hugepage_global_enabled())
 		return true;
 	if (IS_ENABLED(CONFIG_SHMEM) && shmem_hpage_pmd_enabled())
@@ -490,7 +490,7 @@ void khugepaged_enter_vma(struct vm_area
 			  vm_flags_t vm_flags)
 {
 	if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags) &&
-	    hugepage_pmd_enabled()) {
+	    hugepage_enabled()) {
 		unsigned long orders = vma_is_anonymous(vma) ?
 					THP_ORDERS_ALL_ANON : BIT(PMD_ORDER);
 
@@ -2702,7 +2702,7 @@ breakouterloop_mmap_lock:
 
 static int khugepaged_has_work(void)
 {
-	return !list_empty(&khugepaged_scan.mm_head) && hugepage_pmd_enabled();
+	return !list_empty(&khugepaged_scan.mm_head) && hugepage_enabled();
 }
 
 static int khugepaged_wait_event(void)
@@ -2775,7 +2775,7 @@ static void khugepaged_wait_work(void)
 		return;
 	}
 
-	if (hugepage_pmd_enabled())
+	if (hugepage_enabled())
 		wait_event_freezable(khugepaged_wait, khugepaged_wait_event());
 }
 
@@ -2806,7 +2806,7 @@ static void set_recommended_min_free_kby
 	int nr_zones = 0;
 	unsigned long recommended_min;
 
-	if (!hugepage_pmd_enabled()) {
+	if (!hugepage_enabled()) {
 		calculate_min_free_kbytes();
 		goto update_wmarks;
 	}
@@ -2856,7 +2856,7 @@ int start_stop_khugepaged(void)
 	int err = 0;
 
 	mutex_lock(&khugepaged_mutex);
-	if (hugepage_pmd_enabled()) {
+	if (hugepage_enabled()) {
 		if (!khugepaged_thread)
 			khugepaged_thread = kthread_run(khugepaged, NULL,
 							"khugepaged");
@@ -2882,7 +2882,7 @@ fail:
 void khugepaged_min_free_kbytes_update(void)
 {
 	mutex_lock(&khugepaged_mutex);
-	if (hugepage_pmd_enabled() && khugepaged_thread)
+	if (hugepage_enabled() && khugepaged_thread)
 		set_recommended_min_free_kbytes();
 	mutex_unlock(&khugepaged_mutex);
 }
_

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

mm-fix-the-inaccurate-memory-statistics-issue-for-users.patch
selftests-khugepaged-fix-the-shmem-collapse-failure.patch
selftests-mm-add-shmem-collapse-as-a-default-test-item.patch
mm-huge_memory-fix-the-check-for-allowed-huge-orders-in-shmem.patch
khugepaged-allow-khugepaged-to-check-all-anonymous-mthp-orders.patch
khugepaged-kick-khugepaged-for-enabling-none-pmd-sized-mthps.patch