The patch titled
Subject: mm: non-pmd-mappable, large folios for folio_add_new_anon_rmap()
has been added to the -mm mm-unstable branch. Its filename is
mm-non-pmd-mappable-large-folios-for-folio_add_new_anon_rmap.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-non-pmd-mappable-large-folios-for-folio_add_new_anon_rmap.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: Ryan Roberts <ryan.roberts@xxxxxxx>
Subject: mm: non-pmd-mappable, large folios for folio_add_new_anon_rmap()
Date: Thu, 7 Dec 2023 16:12:03 +0000
In preparation for supporting anonymous multi-size THP, improve
folio_add_new_anon_rmap() to allow a non-pmd-mappable, large folio to be
passed to it. In this case, all contained pages are accounted using the
order-0 folio (or base page) scheme.
Link: https://lkml.kernel.org/r/20231207161211.2374093-3-ryan.roberts@xxxxxxx
Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx>
Reviewed-by: Yu Zhao <yuzhao@xxxxxxxxxx>
Reviewed-by: Yin Fengwei <fengwei.yin@xxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Barry Song <v-songbaohua@xxxxxxxx>
Tested-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Tested-by: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Itaru Kitayama <itaru.kitayama@xxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/rmap.c | 28 ++++++++++++++++++++--------
1 file changed, 20 insertions(+), 8 deletions(-)
--- a/mm/rmap.c~mm-non-pmd-mappable-large-folios-for-folio_add_new_anon_rmap
+++ a/mm/rmap.c
@@ -1352,32 +1352,44 @@ void page_add_anon_rmap(struct page *pag
* This means the inc-and-test can be bypassed.
* The folio does not have to be locked.
*
- * If the folio is large, it is accounted as a THP. As the folio
+ * If the folio is pmd-mappable, it is accounted as a THP. As the folio
* is new, it's assumed to be mapped exclusively by a single process.
*/
void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *vma,
unsigned long address)
{
- int nr;
+ int nr = folio_nr_pages(folio);
- VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma);
+ VM_BUG_ON_VMA(address < vma->vm_start ||
+ address + (nr << PAGE_SHIFT) > vma->vm_end, vma);
__folio_set_swapbacked(folio);
+ __folio_set_anon(folio, vma, address, true);
- if (likely(!folio_test_pmd_mappable(folio))) {
+ if (likely(!folio_test_large(folio))) {
/* increment count (starts at -1) */
atomic_set(&folio->_mapcount, 0);
- nr = 1;
+ SetPageAnonExclusive(&folio->page);
+ } else if (!folio_test_pmd_mappable(folio)) {
+ int i;
+
+ for (i = 0; i < nr; i++) {
+ struct page *page = folio_page(folio, i);
+
+ /* increment count (starts at -1) */
+ atomic_set(&page->_mapcount, 0);
+ SetPageAnonExclusive(page);
+ }
+
+ atomic_set(&folio->_nr_pages_mapped, nr);
} else {
/* increment count (starts at -1) */
atomic_set(&folio->_entire_mapcount, 0);
atomic_set(&folio->_nr_pages_mapped, COMPOUND_MAPPED);
- nr = folio_nr_pages(folio);
+ SetPageAnonExclusive(&folio->page);
__lruvec_stat_mod_folio(folio, NR_ANON_THPS, nr);
}
__lruvec_stat_mod_folio(folio, NR_ANON_MAPPED, nr);
- __folio_set_anon(folio, vma, address, true);
- SetPageAnonExclusive(&folio->page);
}
/**
_
Patches currently in -mm which might be from ryan.roberts@xxxxxxx are
mm-readahead-do-not-allow-order-1-folio.patch
mm-allow-deferred-splitting-of-arbitrary-anon-large-folios.patch
mm-non-pmd-mappable-large-folios-for-folio_add_new_anon_rmap.patch
mm-thp-introduce-multi-size-thp-sysfs-interface.patch
mm-thp-support-allocation-of-anonymous-multi-size-thp.patch
selftests-mm-kugepaged-restore-thp-settings-at-exit.patch
selftests-mm-factor-out-thp-settings-management.patch
selftests-mm-support-multi-size-thp-interface-in-thp_settings.patch
selftests-mm-khugepaged-enlighten-for-multi-size-thp.patch
selftests-mm-cow-generalize-do_run_with_thp-helper.patch
selftests-mm-cow-add-tests-for-anonymous-multi-size-thp.patch
