The patch titled
Subject: mm/memory: further separate anon and pagecache folio handling in zap_present_pte()
has been added to the -mm mm-unstable branch. Its filename is
mm-memory-further-separate-anon-and-pagecache-folio-handling-in-zap_present_pte.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-memory-further-separate-anon-and-pagecache-folio-handling-in-zap_present_pte.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@xxxxxxxxxx>
Subject: mm/memory: further separate anon and pagecache folio handling in zap_present_pte()
Date: Wed, 14 Feb 2024 21:44:28 +0100
We don't need up-to-date accessed-dirty information for anon folios and
can simply work with the ptent we already have. Also, we know the RSS
counter we want to update.
We can safely move arch_check_zapped_pte() + tlb_remove_tlb_entry() +
zap_install_uffd_wp_if_needed() after updating the folio and RSS.
While at it, only call zap_install_uffd_wp_if_needed() if there is even
any chance that pte_install_uffd_wp_if_needed() would do *something*.
That is, just don't bother if uffd-wp does not apply.
Link: https://lkml.kernel.org/r/20240214204435.167852-4-david@xxxxxxxxxx
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: "Naveen N. Rao" <naveen.n.rao@xxxxxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Sven Schnelle <svens@xxxxxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Yin Fengwei <fengwei.yin@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
--- a/mm/memory.c~mm-memory-further-separate-anon-and-pagecache-folio-handling-in-zap_present_pte
+++ a/mm/memory.c
@@ -1552,12 +1552,9 @@ static inline void zap_present_pte(struc
folio = page_folio(page);
if (unlikely(!should_zap_folio(details, folio)))
return;
- ptent = ptep_get_and_clear_full(mm, addr, pte, tlb->fullmm);
- arch_check_zapped_pte(vma, ptent);
- tlb_remove_tlb_entry(tlb, pte, addr);
- zap_install_uffd_wp_if_needed(vma, addr, pte, details, ptent);
if (!folio_test_anon(folio)) {
+ ptent = ptep_get_and_clear_full(mm, addr, pte, tlb->fullmm);
if (pte_dirty(ptent)) {
folio_mark_dirty(folio);
if (tlb_delay_rmap(tlb)) {
@@ -1567,8 +1564,17 @@ static inline void zap_present_pte(struc
}
if (pte_young(ptent) && likely(vma_has_recency(vma)))
folio_mark_accessed(folio);
+ rss[mm_counter(folio)]--;
+ } else {
+ /* We don't need up-to-date accessed/dirty bits. */
+ ptep_get_and_clear_full(mm, addr, pte, tlb->fullmm);
+ rss[MM_ANONPAGES]--;
}
- rss[mm_counter(folio)]--;
+ arch_check_zapped_pte(vma, ptent);
+ tlb_remove_tlb_entry(tlb, pte, addr);
+ if (unlikely(userfaultfd_pte_wp(vma, ptent)))
+ zap_install_uffd_wp_if_needed(vma, addr, pte, details, ptent);
+
if (!delay_rmap) {
folio_remove_rmap_pte(folio, page, vma);
if (unlikely(page_mapcount(page) < 0))
_
Patches currently in -mm which might be from david@xxxxxxxxxx are
arm-pgtable-define-pfn_pte_shift.patch
nios2-pgtable-define-pfn_pte_shift.patch
powerpc-pgtable-define-pfn_pte_shift.patch
riscv-pgtable-define-pfn_pte_shift.patch
s390-pgtable-define-pfn_pte_shift.patch
sparc-pgtable-define-pfn_pte_shift.patch
mm-pgtable-make-pte_next_pfn-independent-of-set_ptes.patch
arm-mm-use-pte_next_pfn-in-set_ptes.patch
powerpc-mm-use-pte_next_pfn-in-set_ptes.patch
mm-memory-factor-out-copying-the-actual-pte-in-copy_present_pte.patch
mm-memory-pass-pte-to-copy_present_pte.patch
mm-memory-optimize-fork-with-pte-mapped-thp.patch
mm-memory-ignore-dirty-accessed-soft-dirty-bits-in-folio_pte_batch.patch
mm-memory-ignore-writable-bit-in-folio_pte_batch.patch
mm-memory-factor-out-zapping-of-present-pte-into-zap_present_pte.patch
mm-memory-handle-page-case-in-zap_present_pte-separately.patch
mm-memory-further-separate-anon-and-pagecache-folio-handling-in-zap_present_pte.patch
mm-memory-factor-out-zapping-folio-pte-into-zap_present_folio_pte.patch
mm-mmu_gather-pass-delay_rmap-instead-of-encoded-page-to-__tlb_remove_page_size.patch
mm-mmu_gather-define-encoded_page_flag_delay_rmap.patch
mm-mmu_gather-add-tlb_remove_tlb_entries.patch
mm-mmu_gather-add-__tlb_remove_folio_pages.patch
mm-mmu_gather-improve-cond_resched-handling-with-large-folios-and-expensive-page-freeing.patch
mm-memory-optimize-unmap-zap-with-pte-mapped-thp.patch
