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Howlett" , Zi Yan , Jonathan Corbet , Shuah Khan , Sean Christopherson , Paolo Bonzini , 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 00/12] userfaultfd: working set tracking for VM guest memory Message-ID: References: <20260414142354.1465950-1-kas@kernel.org> <55019037-4f1c-4d9c-83ee-3a844d8f3d5e@kernel.org> <1a499781-1115-44bc-adbf-2ac3769354ca@kernel.org> <4c635703-3d8d-4cfa-bb98-7f6f5fcbe547@kernel.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Fri, Apr 17, 2026 at 01:26:34PM +0100, Kiryl Shutsemau wrote: > > Leaving NUMA-balancing aside, a simple > > mprotect(PROT_NONE)+mprotect(PROT_READ) would already be problematic to > > distinguish both cases. > > Hm. I didn't consider this case (miss some uffd lore). Will rework to > reuse existing PTE bit. See https://git.kernel.org/pub/scm/linux/kernel/git/kas/linux.git uffd/rfc-v3 -- Kiryl Shutsemau / Kirill A. Shutemov