+ mm-pgtable-correct-the-wrong-comment-about-ptdesc-__page_flags.patch added to mm-unstable branch

+ mm-pgtable-correct-the-wrong-comment-about-ptdesc-__page_flags.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: pgtable: correct the wrong comment about ptdesc->__page_flags
has been added to the -mm mm-unstable branch.  Its filename is
     mm-pgtable-correct-the-wrong-comment-about-ptdesc-__page_flags.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-pgtable-correct-the-wrong-comment-about-ptdesc-__page_flags.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: Qi Zheng <zhengqi.arch@bytedance.com>
Subject: mm: pgtable: correct the wrong comment about ptdesc->__page_flags
Date: Mon, 4 Mar 2024 19:07:18 +0800

Patch series "minor fixes and supplement for ptdesc".

In this series, the [PATCH 1/3] and [PATCH 2/3] are fixes for some issues
discovered during code inspection.

The [PATCH 3/3] is a supplement to ptdesc conversion in s390, I don't know
why this is not done in the commit 6326c26c1514 ("s390: convert various
pgalloc functions to use ptdescs"), maybe I missed something.  And since I
don't have an s390 environment, I hope kernel test robot can help compile
and test, and this is why I did not fold [PATCH 2/3] and [PATCH 3/3] into
one patch.


This patch (of 3):

The commit 32cc0b7c9d50 ("powerpc: add pte_free_defer() for pgtables
sharing page") introduced the use of PageActive flag to page table
fragments tracking, so the ptdesc->__page_flags is not unused, so correct
the wrong comment.

Link: https://lkml.kernel.org/r/cover.1709541697.git.zhengqi.arch@bytedance.com
Link: https://lkml.kernel.org/r/cc42d5915fd98fd802f920de243f535efcfe01db.1709541697.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/mm_types.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/include/linux/mm_types.h~mm-pgtable-correct-the-wrong-comment-about-ptdesc-__page_flags
+++ a/include/linux/mm_types.h
@@ -419,7 +419,7 @@ FOLIO_MATCH(compound_head, _head_2a);
 
 /**
  * struct ptdesc -    Memory descriptor for page tables.
- * @__page_flags:     Same as page flags. Unused for page tables.
+ * @__page_flags:     Same as page flags. Powerpc only.
  * @pt_rcu_head:      For freeing page table pages.
  * @pt_list:          List of used page tables. Used for s390 and x86.
  * @_pt_pad_1:        Padding that aliases with page's compound head.
_

Patches currently in -mm which might be from zhengqi.arch@bytedance.com are

mm-userfaultfd-fix-unexpected-change-to-src_folio-when-uffdio_move-fails.patch
mm-pgtable-correct-the-wrong-comment-about-ptdesc-__page_flags.patch
mm-pgtable-add-missing-pt_index-to-struct-ptdesc.patch
s390-supplement-for-ptdesc-conversion.patch