From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
Hugh Dickins <hughd@google.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
David Rientjes <rientjes@google.com>,
Shakeel Butt <shakeelb@google.com>,
John Hubbard <jhubbard@nvidia.com>,
Jason Gunthorpe <jgg@nvidia.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
Mike Rapoport <rppt@linux.ibm.com>,
Yang Shi <shy828301@gmail.com>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
Matthew Wilcox <willy@infradead.org>,
Vlastimil Babka <vbabka@suse.cz>, Jann Horn <jannh@google.com>,
Michal Hocko <mhocko@kernel.org>, Nadav Amit <namit@vmware.com>,
Rik van Riel <riel@surriel.com>, Roman Gushchin <guro@fb.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Peter Xu <peterx@redhat.com>, Donald Dutile <ddutile@redhat.com>,
Christoph Hellwig <hch@lst.de>, Oleg Nesterov <oleg@redhat.com>,
Jan Kara <jack@suse.cz>, Liang Zhang <zhangliang5@huawei.com>,
Pedro Gomes <pedrodemargomes@gmail.com>,
Oded Gabbay <oded.gabbay@gmail.com>,
linux-mm@kvack.org, David Hildenbrand <david@redhat.com>
Subject: [PATCH v2 09/15] mm/rmap: use page_move_anon_rmap() when reusing a mapped PageAnon() page exclusively
Date: Tue, 15 Mar 2022 11:47:35 +0100 [thread overview]
Message-ID: <20220315104741.63071-10-david@redhat.com> (raw)
In-Reply-To: <20220315104741.63071-1-david@redhat.com>
We want to mark anonymous pages exclusive, and when using
page_move_anon_rmap() we know that we are the exclusive user, as
properly documented. This is a preparation for marking anonymous pages
exclusive in page_move_anon_rmap().
In both instances, we're holding page lock and are sure that we're the
exclusive owner (page_count() == 1). hugetlb already properly uses
page_move_anon_rmap() in the write fault handler.
Note that in case of a PTE-mapped THP, we'll only end up calling this
function if the whole THP is only referenced by the single PTE mapping
a single subpage (page_count() == 1); consequently, it's fine to modify
the compound page mapping inside page_move_anon_rmap().
Signed-off-by: David Hildenbrand <david@redhat.com>
---
mm/huge_memory.c | 2 ++
mm/memory.c | 1 +
2 files changed, 3 insertions(+)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index c1f7eaba23ff..0b6fb409b9e4 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1317,6 +1317,8 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf)
try_to_free_swap(page);
if (page_count(page) == 1) {
pmd_t entry;
+
+ page_move_anon_rmap(page, vma);
entry = pmd_mkyoung(orig_pmd);
entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
if (pmdp_set_access_flags(vma, haddr, vmf->pmd, entry, 1))
diff --git a/mm/memory.c b/mm/memory.c
index 00c45b3a9576..7b32f422798d 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3307,6 +3307,7 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf)
* and the page is locked, it's dark out, and we're wearing
* sunglasses. Hit it.
*/
+ page_move_anon_rmap(page, vma);
unlock_page(page);
wp_page_reuse(vmf);
return VM_FAULT_WRITE;
--
2.35.1
next prev parent reply other threads:[~2022-03-15 10:52 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-15 10:47 [PATCH v2 00/15] mm: COW fixes part 2: reliable GUP pins of anonymous pages David Hildenbrand
2022-03-15 10:47 ` [PATCH v2 01/15] mm/rmap: fix missing swap_free() in try_to_unmap() after arch_unmap_one() failed David Hildenbrand
2022-03-29 13:59 ` David Hildenbrand
2022-03-29 20:42 ` Khalid Aziz
2022-03-29 20:55 ` David Hildenbrand
2022-03-30 17:04 ` Khalid Aziz
2022-03-31 13:46 ` David Hildenbrand
2022-03-15 10:47 ` [PATCH v2 02/15] mm/hugetlb: take src_mm->write_protect_seq in copy_hugetlb_page_range() David Hildenbrand
2022-03-15 10:47 ` [PATCH v2 03/15] mm/memory: slightly simplify copy_present_pte() David Hildenbrand
2022-03-15 10:47 ` [PATCH v2 04/15] mm/rmap: split page_dup_rmap() into page_dup_file_rmap() and page_try_dup_anon_rmap() David Hildenbrand
2022-03-16 20:02 ` Yang Shi
2022-03-17 9:00 ` David Hildenbrand
2022-03-15 10:47 ` [PATCH v2 05/15] mm/rmap: convert RMAP flags to a proper distinct rmap_t type David Hildenbrand
2022-03-15 10:47 ` [PATCH v2 06/15] mm/rmap: remove do_page_add_anon_rmap() David Hildenbrand
2022-03-15 10:47 ` [PATCH v2 07/15] mm/rmap: pass rmap flags to hugepage_add_anon_rmap() David Hildenbrand
2022-03-15 10:47 ` [PATCH v2 08/15] mm/rmap: drop "compound" parameter from page_add_new_anon_rmap() David Hildenbrand
2022-03-15 10:47 ` David Hildenbrand [this message]
2022-03-15 10:47 ` [PATCH v2 10/15] mm/page-flags: reuse PG_mappedtodisk as PG_anon_exclusive for PageAnon() pages David Hildenbrand
2022-03-15 10:47 ` [PATCH v2 11/15] mm: remember exclusively mapped anonymous pages with PG_anon_exclusive David Hildenbrand
2022-03-16 21:23 ` Yang Shi
2022-03-17 9:06 ` David Hildenbrand
2022-03-18 20:29 ` Yang Shi
2022-03-19 10:21 ` David Hildenbrand
2022-03-19 10:50 ` David Hildenbrand
2022-03-21 20:56 ` Yang Shi
2022-03-22 9:41 ` David Hildenbrand
2022-03-21 20:51 ` Yang Shi
2022-03-15 10:47 ` [PATCH v2 12/15] mm/gup: disallow follow_page(FOLL_PIN) David Hildenbrand
2022-03-15 10:47 ` [PATCH v2 13/15] mm: support GUP-triggered unsharing of anonymous pages David Hildenbrand
2022-03-18 23:30 ` Jason Gunthorpe
2022-03-21 16:15 ` David Hildenbrand
2022-03-21 16:18 ` Jason Gunthorpe
2022-03-21 16:24 ` David Hildenbrand
2022-03-15 10:47 ` [PATCH v2 14/15] mm/gup: trigger FAULT_FLAG_UNSHARE when R/O-pinning a possibly shared anonymous page David Hildenbrand
2022-03-15 10:47 ` [PATCH v2 15/15] mm/gup: sanity-check with CONFIG_DEBUG_VM that anonymous pages are exclusive when (un)pinning David Hildenbrand
2022-03-18 23:35 ` Jason Gunthorpe
2022-03-19 10:22 ` David Hildenbrand
2022-03-18 23:36 ` [PATCH v2 00/15] mm: COW fixes part 2: reliable GUP pins of anonymous pages Jason Gunthorpe
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