From: Kiryl Shutsemau <kas@kernel.org>
To: Usama Arif <usama.arif@linux.dev>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Peter Xu <peterx@redhat.com>,
David Hildenbrand <david@kernel.org>,
Lorenzo Stoakes <ljs@kernel.org>,
Mike Rapoport <rppt@kernel.org>,
Suren Baghdasaryan <surenb@google.com>,
Vlastimil Babka <vbabka@kernel.org>,
"Liam R . Howlett" <Liam.Howlett@oracle.com>,
Zi Yan <ziy@nvidia.com>, Jonathan Corbet <corbet@lwn.net>,
Shuah Khan <skhan@linuxfoundation.org>,
Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org,
kvm@vger.kernel.org
Subject: Re: [RFC, PATCH 10/12] userfaultfd: add UFFDIO_SET_MODE for runtime sync/async toggle
Date: Thu, 16 Apr 2026 14:27:17 +0100 [thread overview]
Message-ID: <aeDje8vylad8bGoj@thinkstation> (raw)
In-Reply-To: <20260415150900.3660575-1-usama.arif@linux.dev>
On Wed, Apr 15, 2026 at 08:08:59AM -0700, Usama Arif wrote:
> > + /* only toggleable features are allowed */
> > + if ((mode.enable | mode.disable) & ~UFFD_FEATURE_TOGGLEABLE)
> > + return -EINVAL;
>
> The commit message states "Only async features that were enabled at
> UFFDIO_API time may be toggled." However, the code only checks that
> the requested feature is in UFFD_FEATURE_TOGGLEABLE.
>
> Is it intentional that a user who opened a uffd without
> UFFD_FEATURE_MINOR_ASYNC can still enable it later via
> UFFDIO_SET_MODE?
The comment is stale. Will fix.
--
Kiryl Shutsemau / Kirill A. Shutemov
next prev parent reply other threads:[~2026-04-16 13:27 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-14 14:23 [RFC, PATCH 00/12] userfaultfd: working set tracking for VM guest memory Kiryl Shutsemau (Meta)
2026-04-14 14:23 ` [RFC, PATCH 01/12] userfaultfd: define UAPI constants for anonymous minor faults Kiryl Shutsemau (Meta)
2026-04-14 14:23 ` [RFC, PATCH 02/12] userfaultfd: add UFFD_FEATURE_MINOR_ANON registration support Kiryl Shutsemau (Meta)
2026-04-14 14:23 ` [RFC, PATCH 03/12] userfaultfd: implement UFFDIO_DEACTIVATE ioctl Kiryl Shutsemau (Meta)
2026-04-14 14:23 ` [RFC, PATCH 04/12] userfaultfd: UFFDIO_CONTINUE for anonymous memory Kiryl Shutsemau (Meta)
2026-04-14 14:23 ` [RFC, PATCH 05/12] mm: intercept protnone faults on VM_UFFD_MINOR anonymous VMAs Kiryl Shutsemau (Meta)
2026-04-14 14:23 ` [RFC, PATCH 06/12] userfaultfd: auto-resolve shmem and hugetlbfs minor faults in async mode Kiryl Shutsemau (Meta)
2026-04-14 14:23 ` [RFC, PATCH 07/12] sched/numa: skip scanning anonymous VM_UFFD_MINOR VMAs Kiryl Shutsemau (Meta)
2026-04-14 14:23 ` [RFC, PATCH 08/12] userfaultfd: enable UFFD_FEATURE_MINOR_ANON Kiryl Shutsemau (Meta)
2026-04-14 14:23 ` [RFC, PATCH 09/12] mm/pagemap: add PAGE_IS_UFFD_DEACTIVATED to PAGEMAP_SCAN Kiryl Shutsemau (Meta)
2026-04-14 14:23 ` [RFC, PATCH 10/12] userfaultfd: add UFFDIO_SET_MODE for runtime sync/async toggle Kiryl Shutsemau (Meta)
2026-04-15 15:08 ` Usama Arif
2026-04-16 13:27 ` Kiryl Shutsemau [this message]
2026-04-14 14:23 ` [RFC, PATCH 11/12] selftests/mm: add userfaultfd anonymous minor fault tests Kiryl Shutsemau (Meta)
2026-04-14 14:23 ` [RFC, PATCH 12/12] Documentation/userfaultfd: document working set tracking Kiryl Shutsemau (Meta)
2026-04-14 15:28 ` [RFC, PATCH 00/12] userfaultfd: working set tracking for VM guest memory Peter Xu
2026-04-14 17:08 ` Kiryl Shutsemau
2026-04-14 17:45 ` Peter Xu
2026-04-14 15:37 ` David Hildenbrand (Arm)
2026-04-14 17:10 ` Kiryl Shutsemau
2026-04-16 13:49 ` Kiryl Shutsemau
2026-04-16 18:32 ` David Hildenbrand (Arm)
2026-04-16 20:25 ` Kiryl Shutsemau
2026-04-17 11:02 ` Kiryl Shutsemau
2026-04-17 11:43 ` David Hildenbrand (Arm)
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