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mm/rmap: rename COMPOUND_MAPPED to ENTIRELY_MAPPED 

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: 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>
This commit is contained in:
David Hildenbrand 2023-12-20 23:45:03 +01:00 committed by Andrew Morton
parent e3b4b1374f
commit e78a13fd16
3 changed files with 13 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Documentation/mm/transhuge.rst
View File

@ -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

6
mm/internal.h
View File

@ -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

18
mm/rmap.c
View File

@ -1172,7 +1172,7 @@ 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)
@ -1182,15 +1182,15 @@ 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;
}
}
@ -1433,7 +1433,7 @@ 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);
}
@ -1514,7 +1514,7 @@ 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)
@ -1524,15 +1524,15 @@ 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;
}
}