From: Mike Rapoport <rppt@kernel.org>
To: linux-mm@kvack.org
Cc: Andrea Arcangeli <aarcange@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Axel Rasmussen <axelrasmussen@google.com>,
Baolin Wang <baolin.wang@linux.alibaba.com>,
David Hildenbrand <david@redhat.com>,
Hugh Dickins <hughd@google.com>,
James Houghton <jthoughton@google.com>,
"Liam R. Howlett" <Liam.Howlett@oracle.com>,
Lorenzo Stoakes <lorenzo.stoakes@oracle.com>,
Michal Hocko <mhocko@suse.com>, Mike Rapoport <rppt@kernel.org>,
Muchun Song <muchun.song@linux.dev>,
Nikita Kalyazin <kalyazin@amazon.com>,
Oscar Salvador <osalvador@suse.de>,
Paolo Bonzini <pbonzini@redhat.com>, Peter Xu <peterx@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Shuah Khan <shuah@kernel.org>,
Suren Baghdasaryan <surenb@google.com>,
Vlastimil Babka <vbabka@suse.cz>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
linux-kselftest@vger.kernel.org,
"David Hildenbrand (Red Hat)" <david@kernel.org>
Subject: [PATCH RFC 06/17] userfaultfd: move vma_can_userfault out of line
Date: Tue, 27 Jan 2026 21:29:25 +0200 [thread overview]
Message-ID: <20260127192936.1250096-7-rppt@kernel.org> (raw)
In-Reply-To: <20260127192936.1250096-1-rppt@kernel.org>
From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
vma_can_userfault() has grown pretty big and it's not called on
performance critical path.
Move it out of line.
No functional changes.
Reviewed-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
include/linux/userfaultfd_k.h | 35 ++---------------------------------
mm/userfaultfd.c | 33 +++++++++++++++++++++++++++++++++
2 files changed, 35 insertions(+), 33 deletions(-)
diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index fd5f42765497..a49cf750e803 100644
--- a/include/linux/userfaultfd_k.h
+++ b/include/linux/userfaultfd_k.h
@@ -208,39 +208,8 @@ static inline bool userfaultfd_armed(struct vm_area_struct *vma)
return vma->vm_flags & __VM_UFFD_FLAGS;
}
-static inline bool vma_can_userfault(struct vm_area_struct *vma,
- vm_flags_t vm_flags,
- bool wp_async)
-{
- vm_flags &= __VM_UFFD_FLAGS;
-
- if (vma->vm_flags & VM_DROPPABLE)
- return false;
-
- if ((vm_flags & VM_UFFD_MINOR) &&
- (!is_vm_hugetlb_page(vma) && !vma_is_shmem(vma)))
- return false;
-
- /*
- * If wp async enabled, and WP is the only mode enabled, allow any
- * memory type.
- */
- if (wp_async && (vm_flags == VM_UFFD_WP))
- return true;
-
- /*
- * If user requested uffd-wp but not enabled pte markers for
- * uffd-wp, then shmem & hugetlbfs are not supported but only
- * anonymous.
- */
- if (!uffd_supports_wp_marker() && (vm_flags & VM_UFFD_WP) &&
- !vma_is_anonymous(vma))
- return false;
-
- /* By default, allow any of anon|shmem|hugetlb */
- return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma) ||
- vma_is_shmem(vma);
-}
+bool vma_can_userfault(struct vm_area_struct *vma, vm_flags_t vm_flags,
+ bool wp_async);
static inline bool vma_has_uffd_without_event_remap(struct vm_area_struct *vma)
{
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 01a2b898fa40..786f0a245675 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -2016,6 +2016,39 @@ ssize_t move_pages(struct userfaultfd_ctx *ctx, unsigned long dst_start,
return moved ? moved : err;
}
+bool vma_can_userfault(struct vm_area_struct *vma, vm_flags_t vm_flags,
+ bool wp_async)
+{
+ vm_flags &= __VM_UFFD_FLAGS;
+
+ if (vma->vm_flags & VM_DROPPABLE)
+ return false;
+
+ if ((vm_flags & VM_UFFD_MINOR) &&
+ (!is_vm_hugetlb_page(vma) && !vma_is_shmem(vma)))
+ return false;
+
+ /*
+ * If wp async enabled, and WP is the only mode enabled, allow any
+ * memory type.
+ */
+ if (wp_async && (vm_flags == VM_UFFD_WP))
+ return true;
+
+ /*
+ * If user requested uffd-wp but not enabled pte markers for
+ * uffd-wp, then shmem & hugetlbfs are not supported but only
+ * anonymous.
+ */
+ if (!uffd_supports_wp_marker() && (vm_flags & VM_UFFD_WP) &&
+ !vma_is_anonymous(vma))
+ return false;
+
+ /* By default, allow any of anon|shmem|hugetlb */
+ return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma) ||
+ vma_is_shmem(vma);
+}
+
static void userfaultfd_set_vm_flags(struct vm_area_struct *vma,
vm_flags_t vm_flags)
{
--
2.51.0
next prev parent reply other threads:[~2026-01-27 19:30 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-27 19:29 [PATCH RFC 00/17] mm, kvm: allow uffd suppot in guest_memfd Mike Rapoport
2026-01-27 19:29 ` [PATCH RFC 01/17] userfaultfd: introduce mfill_copy_folio_locked() helper Mike Rapoport
2026-02-03 17:45 ` Peter Xu
2026-02-08 9:49 ` Mike Rapoport
2026-01-27 19:29 ` [PATCH RFC 02/17] userfaultfd: introduce struct mfill_state Mike Rapoport
2026-01-27 19:29 ` [PATCH RFC 03/17] userfaultfd: introduce mfill_get_pmd() helper Mike Rapoport
2026-01-27 19:29 ` [PATCH RFC 04/17] userfaultfd: introduce mfill_get_vma() and mfill_put_vma() Mike Rapoport
2026-02-02 21:49 ` Peter Xu
2026-02-08 9:54 ` Mike Rapoport
2026-01-27 19:29 ` [PATCH RFC 05/17] userfaultfd: retry copying with locks dropped in mfill_atomic_pte_copy() Mike Rapoport
2026-02-02 21:23 ` Peter Xu
2026-02-08 10:01 ` Mike Rapoport
2026-01-27 19:29 ` Mike Rapoport [this message]
2026-01-27 19:29 ` [PATCH RFC 07/17] userfaultfd: introduce vm_uffd_ops Mike Rapoport
2026-02-02 21:36 ` Peter Xu
2026-02-08 10:13 ` Mike Rapoport
2026-02-11 19:35 ` Peter Xu
2026-02-15 17:47 ` Mike Rapoport
2026-02-18 21:34 ` Peter Xu
2026-01-27 19:29 ` [PATCH RFC 08/17] userfaultfd, shmem: use a VMA callback to handle UFFDIO_CONTINUE Mike Rapoport
2026-01-27 19:29 ` [PATCH RFC 09/17] userfaultfd: introduce vm_uffd_ops->alloc_folio() Mike Rapoport
2026-02-02 22:13 ` Peter Xu
2026-02-08 10:22 ` Mike Rapoport
2026-02-11 19:37 ` Peter Xu
2026-01-27 19:29 ` [PATCH RFC 10/17] shmem, userfaultfd: implement shmem uffd operations using vm_uffd_ops Mike Rapoport
2026-02-03 17:40 ` Peter Xu
2026-02-08 10:35 ` Mike Rapoport
2026-02-11 20:00 ` Peter Xu
2026-02-15 17:45 ` Mike Rapoport
2026-02-18 21:45 ` Peter Xu
2026-01-27 19:29 ` [PATCH RFC 11/17] userfaultfd: mfill_atomic() remove retry logic Mike Rapoport
2026-01-27 19:29 ` [PATCH RFC 12/17] mm: introduce VM_FAULT_UFFD_MINOR fault reason Mike Rapoport
2026-01-27 19:29 ` [PATCH RFC 13/17] mm: introduce VM_FAULT_UFFD_MISSING " Mike Rapoport
2026-01-27 19:29 ` [PATCH RFC 14/17] KVM: guest_memfd: implement userfaultfd minor mode Mike Rapoport
2026-01-27 19:29 ` [PATCH RFC 15/17] KVM: guest_memfd: implement userfaultfd missing mode Mike Rapoport
2026-01-27 19:29 ` [PATCH RFC 16/17] KVM: selftests: test userfaultfd minor for guest_memfd Mike Rapoport
2026-01-27 19:29 ` [PATCH RFC 17/17] KVM: selftests: test userfaultfd missing " Mike Rapoport
2026-02-03 20:56 ` [PATCH RFC 00/17] mm, kvm: allow uffd suppot in guest_memfd Peter Xu
2026-02-09 15:35 ` David Hildenbrand (Arm)
2026-02-11 6:04 ` Mike Rapoport
2026-02-11 9:52 ` David Hildenbrand (Arm)
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