Commit 8e0cd70c authored by David Hildenbrand's avatar David Hildenbrand Committed by Kefeng Wang
Browse files

mm/rmap: rename COMPOUND_MAPPED to ENTIRELY_MAPPED 

mainline inclusion
from mainline-v6.8-rc1
commit e78a13fd16bb9d9712f61be2bd6612a092ce66ea
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9CESE
CVE: NA

-------------------------------------------------

We removed all "bool compound" and RMAP_COMPOUND parameters.  Let's remove
the remaining "compound" terminology by making COMPOUND_MAPPED match the
"folio->_entire_mapcount" terminology, renaming it to ENTIRELY_MAPPED.

ENTIRELY_MAPPED is only used when the whole folio is mapped using a single
page table entry (e.g., a single PMD mapping a PMD-sized THP).  For now,
we don't support mapping any THP bigger than that, so ENTIRELY_MAPPED only
applies to PMD-mapped PMD-sized THP only.

Link: https://lkml.kernel.org/r/20231220224504.646757-40-david@redhat.com


Signed-off-by: default avatarDavid 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: default avatarAndrew Morton <akpm@linux-foundation.org>
(cherry picked from commit e78a13fd16bb9d9712f61be2bd6612a092ce66ea)
Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
parent d5273510

Documentation/mm/transhuge.rst

+1 −1
Original line number Diff line number Diff line
@@ -117,7 +117,7 @@ pages: 


  - map/unmap of a PMD entry for the whole THP increment/decrement

    folio->_entire_mapcount and also increment/decrement

    folio->_nr_pages_mapped by COMPOUND_MAPPED when _entire_mapcount

    folio->_nr_pages_mapped by ENTIRELY_MAPPED when _entire_mapcount

    goes from -1 to 0 or 0 to -1.



  - map/unmap of individual pages with PTE entry increment/decrement

mm/internal.h

+3 −3
Original line number Diff line number Diff line
@@ -54,12 +54,12 @@ void page_writeback_init(void); 


/*

 * If a 16GB hugetlb folio were mapped by PTEs of all of its 4kB pages,

 * its nr_pages_mapped would be 0x400000: choose the COMPOUND_MAPPED bit

 * its nr_pages_mapped would be 0x400000: choose the ENTIRELY_MAPPED bit

 * above that range, instead of 2*(PMD_SIZE/PAGE_SIZE).  Hugetlb currently

 * leaves nr_pages_mapped at 0, but avoid surprise if it participates later.

 */

#define COMPOUND_MAPPED		0x800000

#define FOLIO_PAGES_MAPPED	(COMPOUND_MAPPED - 1)

#define ENTIRELY_MAPPED		0x800000

#define FOLIO_PAGES_MAPPED	(ENTIRELY_MAPPED - 1)



/*

 * Flags passed to __show_mem() and show_free_areas() to suppress output in

mm/rmap.c

+9 −9
Original line number Diff line number Diff line
@@ -1142,7 +1142,7 @@ static __always_inline unsigned int __folio_add_rmap(struct folio *folio, 
			first = atomic_inc_and_test(&page->_mapcount);

			if (first && folio_test_large(folio)) {

				first = atomic_inc_return_relaxed(mapped);

				first = (first < COMPOUND_MAPPED);

				first = (first < ENTIRELY_MAPPED);

			}



			if (first)
@@ -1152,15 +1152,15 @@ static __always_inline unsigned int __folio_add_rmap(struct folio *folio, 
	case RMAP_LEVEL_PMD:

		first = atomic_inc_and_test(&folio->_entire_mapcount);

		if (first) {

			nr = atomic_add_return_relaxed(COMPOUND_MAPPED, mapped);

			if (likely(nr < COMPOUND_MAPPED + COMPOUND_MAPPED)) {

			nr = atomic_add_return_relaxed(ENTIRELY_MAPPED, mapped);

			if (likely(nr < ENTIRELY_MAPPED + ENTIRELY_MAPPED)) {

				*nr_pmdmapped = folio_nr_pages(folio);

				nr = *nr_pmdmapped - (nr & FOLIO_PAGES_MAPPED);

				/* Raced ahead of a remove and another add? */

				if (unlikely(nr < 0))

					nr = 0;

			} else {

				/* Raced ahead of a remove of COMPOUND_MAPPED */

				/* Raced ahead of a remove of ENTIRELY_MAPPED */

				nr = 0;

			}

		}
@@ -1403,7 +1403,7 @@ void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *vma, 
	} else {

		/* increment count (starts at -1) */

		atomic_set(&folio->_entire_mapcount, 0);

		atomic_set(&folio->_nr_pages_mapped, COMPOUND_MAPPED);

		atomic_set(&folio->_nr_pages_mapped, ENTIRELY_MAPPED);

		SetPageAnonExclusive(&folio->page);

		__lruvec_stat_mod_folio(folio, NR_ANON_THPS, nr);

	}
@@ -1484,7 +1484,7 @@ static __always_inline void __folio_remove_rmap(struct folio *folio, 
			last = atomic_add_negative(-1, &page->_mapcount);

			if (last && folio_test_large(folio)) {

				last = atomic_dec_return_relaxed(mapped);

				last = (last < COMPOUND_MAPPED);

				last = (last < ENTIRELY_MAPPED);

			}



			if (last)
@@ -1494,15 +1494,15 @@ static __always_inline void __folio_remove_rmap(struct folio *folio, 
	case RMAP_LEVEL_PMD:

		last = atomic_add_negative(-1, &folio->_entire_mapcount);

		if (last) {

			nr = atomic_sub_return_relaxed(COMPOUND_MAPPED, mapped);

			if (likely(nr < COMPOUND_MAPPED)) {

			nr = atomic_sub_return_relaxed(ENTIRELY_MAPPED, mapped);

			if (likely(nr < ENTIRELY_MAPPED)) {

				nr_pmdmapped = folio_nr_pages(folio);

				nr = nr_pmdmapped - (nr & FOLIO_PAGES_MAPPED);

				/* Raced ahead of another remove and an add? */

				if (unlikely(nr < 0))

					nr = 0;

			} else {

				/* An add of COMPOUND_MAPPED raced ahead */

				/* An add of ENTIRELY_MAPPED raced ahead */

				nr = 0;

			}

		}