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Thu, 23 Apr 2026 07:50:09 -0700 (PDT) Received: from x1.local ([142.189.10.167]) by smtp.gmail.com with ESMTPSA id af79cd13be357-8e7d98c15a9sm1850297485a.43.2026.04.23.07.50.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Apr 2026 07:50:08 -0700 (PDT) Date: Thu, 23 Apr 2026 10:50:06 -0400 From: Peter Xu To: Kiryl Shutsemau Cc: "David Hildenbrand (Arm)" , Andrew Morton , Lorenzo Stoakes , Mike Rapoport , Suren Baghdasaryan , Vlastimil Babka , "Liam R . 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: <1a499781-1115-44bc-adbf-2ac3769354ca@kernel.org> <4c635703-3d8d-4cfa-bb98-7f6f5fcbe547@kernel.org> <34f75083-29a3-4860-8a6e-94551d37ac6a@kernel.org> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Hello, Kiryl, On Thu, Apr 23, 2026 at 03:27:11PM +0100, Kiryl Shutsemau wrote: > The patchet is pretty good shape in my eyes and will probably drop RFC > tag. I still have some high level questions not yet got answered. Do you want to answer them? https://lore.kernel.org/all/ad59TxAHNwFWH7Cc@x1.local/ In summary, it's about: - Whether we have explored other approaches on page hotness tracking - Whether read protection is required for an userspace swap system (e.g. did you get time to have a look at umap?) Thanks, -- Peter Xu