From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3549AE81A52 for ; Mon, 16 Feb 2026 17:10:22 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 671D46B0088; Mon, 16 Feb 2026 12:10:21 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 61F266B0089; Mon, 16 Feb 2026 12:10:21 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 501096B008A; Mon, 16 Feb 2026 12:10:21 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 3944B6B0088 for ; Mon, 16 Feb 2026 12:10:21 -0500 (EST) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id B44E51D061 for ; Mon, 16 Feb 2026 17:10:20 +0000 (UTC) X-FDA: 84450958200.02.3BC4303 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf01.hostedemail.com (Postfix) with ESMTP id E54264000E for ; Mon, 16 Feb 2026 17:10:18 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=UentRwXd; spf=pass (imf01.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1771261818; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=DaQ0OXZDiIGvRtMFwDiNcSnzr/tYNYYL/vIV6lLWmT0=; b=5aeAs/WIbmwwwgiSPWv3QeS+B83oRI2dFjDIN4jC/sErjckrKjNL3YfL1T+RieD1Q+y5sn 3waYz6PBSrTE2nBpQmnbBvAHU+5lJiA/zP221paGPk+uODcKKsXN3yyDCi/7aM+/Y7OBD0 WD8IrqW90lfLiSG+AWitCyMkvoNkC8g= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=UentRwXd; spf=pass (imf01.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1771261818; a=rsa-sha256; cv=none; b=k+ijSKzMpf+cRbX1FPsxfVhQ6FbzU4Z8gFCdIruSjbi07TGXvsg5oQ12sNRsZ5jJ4oaQWb JMaHRtZ2Aiv5SI2EmiJ4GOb3WyWunOKKyxwG5+bAx51RS39A3BfaXZi6vMU2b8df44oQBB wT3kddyvH9M/voPysY7TC2MxA9j56eY= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 2C0966014C; Mon, 16 Feb 2026 17:10:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D1248C116C6; Mon, 16 Feb 2026 17:10:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771261817; bh=v3qrqnJwZA6qFwCA4Mm3NnqaPiKrQfaTE3E7NoIivHc=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=UentRwXdklwDX853Rt/zN+0KaUCEVYjvV9lg6ProwkxjclQIYw5SdN7hPO+by4E49 /qeK9dKOtmi+AK0m9lHRJoPJTUvg3pYN3B9C8xwUgmL0eVGHBSgmRIs1MuDrTxS7x0 6VHpUGKBDOg0Dk/3FG2A2Rju8DPAXUZLrae/07qsM/hWt6gZd/ojr07/dC5C1bnFrk sSjw5kDtBn1aKBcXBshbnCMZNU+AHShTg/+41IddPKEPq+dt3Jmj47+ZMnBr0EByFB 7sYGDzUDlP0BOM7DizK/cEYUu14q8Gqt5F2vV6ZHaPdxMC6zqJ8I9o+byk71PaUV3H qtyI6ITx2TTMw== Message-ID: <18ea1313-1142-47b5-b5b4-5c1403662f86@kernel.org> Date: Mon, 16 Feb 2026 18:10:12 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm: Add AnonZero accounting for zero-filled anonymous pages To: Matthew Wilcox , Kiryl Shutsemau Cc: Wenchao Hao , Andrew Morton , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20260214084514.2842745-1-haowenchao22@gmail.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: 1mfwfrpssyfp17bqejgzin1anxw9moh7 X-Rspamd-Queue-Id: E54264000E X-Rspam-User: X-Rspamd-Server: rspam04 X-HE-Tag: 1771261818-680277 X-HE-Meta: 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 xS/Mlxc3 +nbF3gCy4vyRNrbCOSAU5iTOE9VZI73DlAr5TvsKfBCKqHtLF1SpeiUpO05kx26E+pC3LVxSu5M6Q25anP9UglM+Bi83ZH7K2gf/KKjFwAohW2zzXjRxZZ6FMp4IihqF0EQHLMvrDKVX7pup1EHSg1tCPqlbSdRZpScYdb7K6GQC6S1WkGd9MFg2qQrRHHV4ETN1zKnoKPckndxSldFyAHZ4AIh3vHSPXYm77v2Vr+ogizrTsishrZazVginSIpwHzjoC X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2/16/26 18:01, Matthew Wilcox wrote: > On Mon, Feb 16, 2026 at 04:54:05PM +0000, Kiryl Shutsemau wrote: >> What I would like to see in the kernel is a syscall that return the >> memory stats in binary form. Something like >> >> size_t memstat(int pidfd, struct memstat memstatbuf[], size_t n, >> unsigned long flags, unsigned long start, unsigned long end); >> >> The syscall will fill up to n memstatbufs, one per-VMA. What exactly >> filled there defined by flags. The return value is how many memstatbuf >> is populated. The caller can call it multiple times to walk address >> space it is interested in. >> >> We also can have a flag that mirrors smaps_rollup behaviour and collect >> all the data into a single memstatbuf. > > But is that what we want? Let's say a process allocates a 2MB THP, uses > 12kB of it and then forks. That's just like all of these entries (Rss, Anonymous, KSM) except the Pss ones behave. -- Cheers, David