From: Mike Rapoport <rppt@kernel.org>
To: David Hildenbrand <david@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Andrew Morton <akpm@linux-foundation.org>,
Matthew Wilcox <willy@infradead.org>,
Ryan Roberts <ryan.roberts@arm.com>,
Russell King <linux@armlinux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Dinh Nguyen <dinguyen@kernel.org>,
Michael Ellerman <mpe@ellerman.id.au>,
Nicholas Piggin <npiggin@gmail.com>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
"Aneesh Kumar K.V" <aneesh.kumar@kernel.org>,
"Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Alexander Gordeev <agordeev@linux.ibm.com>,
Gerald Schaefer <gerald.schaefer@linux.ibm.com>,
Heiko Carstens <hca@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
Sven Schnelle <svens@linux.ibm.com>,
"David S. Miller" <davem@davemloft.net>,
linux-arm-kernel@lists.infradead.org,
linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org,
linux-s390@vger.kernel.org, sparclinux@vger.kernel.org
Subject: Re: [PATCH v3 11/15] mm/memory: factor out copying the actual PTE in copy_present_pte()
Date: Thu, 8 Feb 2024 08:29:21 +0200 [thread overview]
Message-ID: <ZcR0waPgUzfQgyGQ@kernel.org> (raw)
In-Reply-To: <20240129124649.189745-12-david@redhat.com>
On Mon, Jan 29, 2024 at 01:46:45PM +0100, David Hildenbrand wrote:
> Let's prepare for further changes.
>
> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
> ---
> mm/memory.c | 63 ++++++++++++++++++++++++++++-------------------------
> 1 file changed, 33 insertions(+), 30 deletions(-)
>
> diff --git a/mm/memory.c b/mm/memory.c
> index 8d14ba440929..a3bdb25f4c8d 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -930,6 +930,29 @@ copy_present_page(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma
> return 0;
> }
>
> +static inline void __copy_present_pte(struct vm_area_struct *dst_vma,
> + struct vm_area_struct *src_vma, pte_t *dst_pte, pte_t *src_pte,
> + pte_t pte, unsigned long addr)
> +{
> + struct mm_struct *src_mm = src_vma->vm_mm;
> +
> + /* If it's a COW mapping, write protect it both processes. */
> + if (is_cow_mapping(src_vma->vm_flags) && pte_write(pte)) {
> + ptep_set_wrprotect(src_mm, addr, src_pte);
> + pte = pte_wrprotect(pte);
> + }
> +
> + /* If it's a shared mapping, mark it clean in the child. */
> + if (src_vma->vm_flags & VM_SHARED)
> + pte = pte_mkclean(pte);
> + pte = pte_mkold(pte);
> +
> + if (!userfaultfd_wp(dst_vma))
> + pte = pte_clear_uffd_wp(pte);
> +
> + set_pte_at(dst_vma->vm_mm, addr, dst_pte, pte);
> +}
> +
> /*
> * Copy one pte. Returns 0 if succeeded, or -EAGAIN if one preallocated page
> * is required to copy this pte.
> @@ -939,23 +962,23 @@ copy_present_pte(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma,
> pte_t *dst_pte, pte_t *src_pte, unsigned long addr, int *rss,
> struct folio **prealloc)
> {
> - struct mm_struct *src_mm = src_vma->vm_mm;
> - unsigned long vm_flags = src_vma->vm_flags;
> pte_t pte = ptep_get(src_pte);
> struct page *page;
> struct folio *folio;
>
> page = vm_normal_page(src_vma, addr, pte);
> - if (page)
> - folio = page_folio(page);
> - if (page && folio_test_anon(folio)) {
> + if (unlikely(!page))
> + goto copy_pte;
> +
> + folio = page_folio(page);
> + folio_get(folio);
> + if (folio_test_anon(folio)) {
> /*
> * If this page may have been pinned by the parent process,
> * copy the page immediately for the child so that we'll always
> * guarantee the pinned page won't be randomly replaced in the
> * future.
> */
> - folio_get(folio);
> if (unlikely(folio_try_dup_anon_rmap_pte(folio, page, src_vma))) {
> /* Page may be pinned, we have to copy. */
> folio_put(folio);
> @@ -963,34 +986,14 @@ copy_present_pte(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma,
> addr, rss, prealloc, page);
> }
> rss[MM_ANONPAGES]++;
> - } else if (page) {
> - folio_get(folio);
> + VM_WARN_ON_FOLIO(PageAnonExclusive(page), folio);
> + } else {
> folio_dup_file_rmap_pte(folio, page);
> rss[mm_counter_file(folio)]++;
> }
>
> - /*
> - * If it's a COW mapping, write protect it both
> - * in the parent and the child
> - */
> - if (is_cow_mapping(vm_flags) && pte_write(pte)) {
> - ptep_set_wrprotect(src_mm, addr, src_pte);
> - pte = pte_wrprotect(pte);
> - }
> - VM_BUG_ON(page && folio_test_anon(folio) && PageAnonExclusive(page));
> -
> - /*
> - * If it's a shared mapping, mark it clean in
> - * the child
> - */
> - if (vm_flags & VM_SHARED)
> - pte = pte_mkclean(pte);
> - pte = pte_mkold(pte);
> -
> - if (!userfaultfd_wp(dst_vma))
> - pte = pte_clear_uffd_wp(pte);
> -
> - set_pte_at(dst_vma->vm_mm, addr, dst_pte, pte);
> +copy_pte:
> + __copy_present_pte(dst_vma, src_vma, dst_pte, src_pte, pte, addr);
> return 0;
> }
>
> --
> 2.43.0
>
>
--
Sincerely yours,
Mike.
_______________________________________________
linux-riscv mailing list
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http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2024-02-08 6:29 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-29 12:46 [PATCH v3 00/15] mm/memory: optimize fork() with PTE-mapped THP David Hildenbrand
2024-01-29 12:46 ` [PATCH v3 01/15] arm64/mm: Make set_ptes() robust when OAs cross 48-bit boundary David Hildenbrand
2024-02-08 6:10 ` Mike Rapoport
2024-02-09 22:36 ` David Hildenbrand
2024-01-29 12:46 ` [PATCH v3 02/15] arm/pgtable: define PFN_PTE_SHIFT David Hildenbrand
2024-02-08 6:11 ` Mike Rapoport
2024-01-29 12:46 ` [PATCH v3 03/15] nios2/pgtable: " David Hildenbrand
2024-02-08 6:12 ` Mike Rapoport
2024-01-29 12:46 ` [PATCH v3 04/15] powerpc/pgtable: " David Hildenbrand
2024-02-08 6:13 ` Mike Rapoport
2024-01-29 12:46 ` [PATCH v3 05/15] riscv/pgtable: " David Hildenbrand
2024-02-08 6:14 ` Mike Rapoport
2024-01-29 12:46 ` [PATCH v3 06/15] s390/pgtable: " David Hildenbrand
2024-02-08 6:15 ` Mike Rapoport
2024-01-29 12:46 ` [PATCH v3 07/15] sparc/pgtable: " David Hildenbrand
2024-02-08 6:18 ` Mike Rapoport
2024-01-29 12:46 ` [PATCH v3 08/15] mm/pgtable: make pte_next_pfn() independent of set_ptes() David Hildenbrand
2024-02-08 6:19 ` Mike Rapoport
2024-01-29 12:46 ` [PATCH v3 09/15] arm/mm: use pte_next_pfn() in set_ptes() David Hildenbrand
2024-02-08 6:20 ` Mike Rapoport
2024-01-29 12:46 ` [PATCH v3 10/15] powerpc/mm: " David Hildenbrand
2024-02-08 6:20 ` Mike Rapoport
2024-01-29 12:46 ` [PATCH v3 11/15] mm/memory: factor out copying the actual PTE in copy_present_pte() David Hildenbrand
2024-02-08 6:29 ` Mike Rapoport [this message]
2024-01-29 12:46 ` [PATCH v3 12/15] mm/memory: pass PTE to copy_present_pte() David Hildenbrand
2024-02-08 6:27 ` Mike Rapoport
2024-02-14 22:40 ` David Hildenbrand
2024-01-29 12:46 ` [PATCH v3 13/15] mm/memory: optimize fork() with PTE-mapped THP David Hildenbrand
2024-02-08 6:41 ` Mike Rapoport
2024-01-29 12:46 ` [PATCH v3 14/15] mm/memory: ignore dirty/accessed/soft-dirty bits in folio_pte_batch() David Hildenbrand
2024-01-29 12:46 ` [PATCH v3 15/15] mm/memory: ignore writable bit " David Hildenbrand
2024-01-31 10:43 ` [PATCH v3 00/15] mm/memory: optimize fork() with PTE-mapped THP Ryan Roberts
2024-01-31 11:06 ` David Hildenbrand
2024-01-31 11:16 ` Ryan Roberts
2024-01-31 11:28 ` David Hildenbrand
2024-01-31 11:49 ` Ryan Roberts
2024-01-31 12:37 ` Ryan Roberts
2024-01-31 12:56 ` David Hildenbrand
2024-01-31 13:16 ` Ryan Roberts
2024-01-31 13:38 ` David Hildenbrand
2024-01-31 13:58 ` Ryan Roberts
2024-01-31 14:29 ` David Hildenbrand
2024-01-31 15:02 ` Ryan Roberts
2024-01-31 15:05 ` David Hildenbrand
2024-01-31 15:08 ` Ryan Roberts
2024-01-31 15:11 ` David Hildenbrand
2024-01-31 12:59 ` David Hildenbrand
2024-03-25 4:42 ` patchwork-bot+linux-riscv
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