+ mm-hugetlb-unify-clearing-of-restorereserve-for-private-pages.patch added to mm-unstable branch

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

The patch titled
     Subject: mm/hugetlb: unify clearing of RestoreReserve for private pages
has been added to the -mm mm-unstable branch.  Its filename is
     mm-hugetlb-unify-clearing-of-restorereserve-for-private-pages.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb-unify-clearing-of-restorereserve-for-private-pages.patch

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

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------------------------------------------------------
From: Peter Xu <peterx@redhat.com>
Subject: mm/hugetlb: unify clearing of RestoreReserve for private pages
Date: Thu, 20 Oct 2022 15:38:32 -0400

A trivial cleanup to move clearing of RestoreReserve into adding anon rmap
of private hugetlb mappings.  It matches with the shared mappings where we
only clear the bit when adding into page cache, rather than spreading it
around the code paths.

Link: https://lkml.kernel.org/r/20221020193832.776173-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/hugetlb.c |   14 ++++----------
 mm/rmap.c    |    2 +-
 2 files changed, 5 insertions(+), 11 deletions(-)

--- a/mm/hugetlb.c~mm-hugetlb-unify-clearing-of-restorereserve-for-private-pages
+++ a/mm/hugetlb.c
@@ -4784,7 +4784,6 @@ hugetlb_install_page(struct vm_area_stru
 	hugepage_add_new_anon_rmap(new_page, vma, addr);
 	set_huge_pte_at(vma->vm_mm, addr, ptep, make_huge_pte(vma, new_page, 1));
 	hugetlb_count_add(pages_per_huge_page(hstate_vma(vma)), vma->vm_mm);
-	ClearHPageRestoreReserve(new_page);
 	SetHPageMigratable(new_page);
 }
 
@@ -5447,8 +5446,6 @@ retry_avoidcopy:
 	spin_lock(ptl);
 	ptep = huge_pte_offset(mm, haddr, huge_page_size(h));
 	if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) {
-		ClearHPageRestoreReserve(new_page);
-
 		/* Break COW or unshare */
 		huge_ptep_clear_flush(vma, haddr, ptep);
 		mmu_notifier_invalidate_range(mm, range.start, range.end);
@@ -5743,10 +5740,9 @@ static vm_fault_t hugetlb_no_page(struct
 	if (!pte_same(huge_ptep_get(ptep), old_pte))
 		goto backout;
 
-	if (anon_rmap) {
-		ClearHPageRestoreReserve(page);
+	if (anon_rmap)
 		hugepage_add_new_anon_rmap(page, vma, haddr);
-	} else
+	else
 		page_dup_file_rmap(page, true);
 	new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE)
 				&& (vma->vm_flags & VM_SHARED)));
@@ -6133,12 +6129,10 @@ int hugetlb_mcopy_atomic_pte(struct mm_s
 	if (!huge_pte_none_mostly(huge_ptep_get(dst_pte)))
 		goto out_release_unlock;
 
-	if (page_in_pagecache) {
+	if (page_in_pagecache)
 		page_dup_file_rmap(page, true);
-	} else {
-		ClearHPageRestoreReserve(page);
+	else
 		hugepage_add_new_anon_rmap(page, dst_vma, dst_addr);
-	}
 
 	/*
 	 * For either: (1) CONTINUE on a non-shared VMA, or (2) UFFDIO_COPY
--- a/mm/rmap.c~mm-hugetlb-unify-clearing-of-restorereserve-for-private-pages
+++ a/mm/rmap.c
@@ -2571,7 +2571,7 @@ void hugepage_add_new_anon_rmap(struct p
 	BUG_ON(address < vma->vm_start || address >= vma->vm_end);
 	atomic_set(compound_mapcount_ptr(page), 0);
 	atomic_set(compound_pincount_ptr(page), 0);
-
+	ClearHPageRestoreReserve(page);
 	__page_set_anon_rmap(page, vma, address, 1);
 }
 #endif /* CONFIG_HUGETLB_PAGE */
_

Patches currently in -mm which might be from peterx@redhat.com are

selftests-vm-use-memfd-for-uffd-hugetlb-tests.patch
selftests-vm-use-memfd-for-hugetlb-madvise-test.patch
selftests-vm-use-memfd-for-hugepage-mremap-test.patch
selftests-vm-drop-mnt-point-for-hugetlb-in-run_vmtestssh.patch
mm-hugetlb-unify-clearing-of-restorereserve-for-private-pages.patch