+ mm-rmap-remove-rmap_compound.patch added to mm-unstable branch

+ mm-rmap-remove-rmap_compound.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/rmap: remove RMAP_COMPOUND
has been added to the -mm mm-unstable branch.  Its filename is
     mm-rmap-remove-rmap_compound.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-rmap-remove-rmap_compound.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: David Hildenbrand <david@redhat.com>
Subject: mm/rmap: remove RMAP_COMPOUND
Date: Wed, 20 Dec 2023 23:44:46 +0100

No longer used, let's remove it and clarify RMAP_NONE/RMAP_EXCLUSIVE a
bit.

Link: https://lkml.kernel.org/r/20231220224504.646757-23-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/rmap.h |   12 +++---------
 mm/rmap.c            |    2 --
 2 files changed, 3 insertions(+), 11 deletions(-)

--- a/include/linux/rmap.h~mm-rmap-remove-rmap_compound
+++ a/include/linux/rmap.h
@@ -177,21 +177,15 @@ struct anon_vma *folio_get_anon_vma(stru
 typedef int __bitwise rmap_t;
 
 /*
- * No special request: if the page is a subpage of a compound page, it is
- * mapped via a PTE. The mapped (sub)page is possibly shared between processes.
+ * No special request: A mapped anonymous (sub)page is possibly shared between
+ * processes.
  */
 #define RMAP_NONE		((__force rmap_t)0)
 
-/* The (sub)page is exclusive to a single process. */
+/* The anonymous (sub)page is exclusive to a single process. */
 #define RMAP_EXCLUSIVE		((__force rmap_t)BIT(0))
 
 /*
- * The compound page is not mapped via PTEs, but instead via a single PMD and
- * should be accounted accordingly.
- */
-#define RMAP_COMPOUND		((__force rmap_t)BIT(1))
-
-/*
  * Internally, we're using an enum to specify the granularity. We make the
  * compiler emit specialized code for each granularity.
  */
--- a/mm/rmap.c~mm-rmap-remove-rmap_compound
+++ a/mm/rmap.c
@@ -2662,8 +2662,6 @@ void rmap_walk_locked(struct folio *foli
  * The following two functions are for anonymous (private mapped) hugepages.
  * Unlike common anonymous pages, anonymous hugepages have no accounting code
  * and no lru code, because we handle hugepages differently from common pages.
- *
- * RMAP_COMPOUND is ignored.
  */
 void hugetlb_add_anon_rmap(struct folio *folio, struct vm_area_struct *vma,
 		unsigned long address, rmap_t flags)
_

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

mm-rmap-rename-hugepage_add-to-hugetlb_add.patch
mm-rmap-introduce-and-use-hugetlb_remove_rmap.patch
mm-rmap-introduce-and-use-hugetlb_add_file_rmap.patch
mm-rmap-introduce-and-use-hugetlb_try_dup_anon_rmap.patch
mm-rmap-introduce-and-use-hugetlb_try_share_anon_rmap.patch
mm-rmap-add-hugetlb-sanity-checks-for-anon-rmap-handling.patch
mm-rmap-convert-folio_add_file_rmap_range-into-folio_add_file_rmap_.patch
mm-memory-page_add_file_rmap-folio_add_file_rmap_.patch
mm-huge_memory-page_add_file_rmap-folio_add_file_rmap_pmd.patch
mm-migrate-page_add_file_rmap-folio_add_file_rmap_pte.patch
mm-userfaultfd-page_add_file_rmap-folio_add_file_rmap_pte.patch
mm-rmap-remove-page_add_file_rmap.patch
mm-rmap-factor-out-adding-folio-mappings-into-__folio_add_rmap.patch
mm-rmap-introduce-folio_add_anon_rmap_.patch
mm-huge_memory-batch-rmap-operations-in-__split_huge_pmd_locked.patch
mm-huge_memory-page_add_anon_rmap-folio_add_anon_rmap_pmd.patch
mm-migrate-page_add_anon_rmap-folio_add_anon_rmap_pte.patch
mm-ksm-page_add_anon_rmap-folio_add_anon_rmap_pte.patch
mm-swapfile-page_add_anon_rmap-folio_add_anon_rmap_pte.patch
mm-memory-page_add_anon_rmap-folio_add_anon_rmap_pte.patch
mm-rmap-remove-page_add_anon_rmap.patch
mm-rmap-remove-rmap_compound.patch
mm-rmap-introduce-folio_remove_rmap_.patch
kernel-events-uprobes-page_remove_rmap-folio_remove_rmap_pte.patch
mm-huge_memory-page_remove_rmap-folio_remove_rmap_pmd.patch
mm-khugepaged-page_remove_rmap-folio_remove_rmap_pte.patch
mm-ksm-page_remove_rmap-folio_remove_rmap_pte.patch
mm-memory-page_remove_rmap-folio_remove_rmap_pte.patch
mm-migrate_device-page_remove_rmap-folio_remove_rmap_pte.patch
mm-rmap-page_remove_rmap-folio_remove_rmap_pte.patch
documentation-stop-referring-to-page_remove_rmap.patch
mm-rmap-remove-page_remove_rmap.patch
mm-rmap-convert-page_dup_file_rmap-to-folio_dup_file_rmap_.patch
mm-rmap-introduce-folio_try_dup_anon_rmap_.patch
mm-huge_memory-page_try_dup_anon_rmap-folio_try_dup_anon_rmap_pmd.patch
mm-memory-page_try_dup_anon_rmap-folio_try_dup_anon_rmap_pte.patch
mm-rmap-remove-page_try_dup_anon_rmap.patch
mm-convert-page_try_share_anon_rmap-to-folio_try_share_anon_rmap_.patch
mm-rmap-rename-compound_mapped-to-entirely_mapped.patch
mm-remove-one-last-reference-to-page_add__rmap.patch