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 60D05F8FA80 for ; Tue, 21 Apr 2026 14:08:04 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CA1F76B0089; Tue, 21 Apr 2026 10:08:03 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C78896B008C; Tue, 21 Apr 2026 10:08:03 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B40D46B0092; Tue, 21 Apr 2026 10:08:03 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id A26E66B0089 for ; Tue, 21 Apr 2026 10:08:03 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 43BFAC401E for ; Tue, 21 Apr 2026 14:08:03 +0000 (UTC) X-FDA: 84682742046.14.C4051D7 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf21.hostedemail.com (Postfix) with ESMTP id 918111C0004 for ; Tue, 21 Apr 2026 14:08:01 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=cvCu5x5u; spf=pass (imf21.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=1776780481; 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=kultI54iHJnpJrmX0ijWuDaC7OkdM11j7gCZi36JyiQ=; b=HPZBUtmV+ZzQeWH3bLaRkcA9Onx9Vhm4cIrqjR1bfhvKasou6K4WddxIe45xiv7Vi5h2Cg YUf6bmYLS+SWOBu6sVV13nUWsRCRAgzaw2kAvbkNTHRFSLQLiPIsb2mjP6aTLFplbbadHE dVIJ7R6cwVI9IqPYiBYs1FNTUAOotw0= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=cvCu5x5u; spf=pass (imf21.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=1776780481; a=rsa-sha256; cv=none; b=C9lBcwMADPZM9PFy5xga93Xdmq7jzBhu0aIx4JTxhedNkFBzDoQFzfLABuPu8A9K9BpUJ1 IcpJXgqzZLC8FLNVJq3eHuG+RN2ffWFDkfdAmmNP1M8U8N6DmJLXj8wAmG+wLmk620lSqW 91L+soFn//avD3pgkDqo7lXox878fG8= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id EF10E6001A; Tue, 21 Apr 2026 14:08:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9FCC3C2BCB0; Tue, 21 Apr 2026 14:07:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776780480; bh=C2vjPG7cYBtC/syRejJLvNATQIcMbGjY9iARX4IFuT8=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=cvCu5x5u/MxJ/rm3ilOI4UDXqGPxauyCd40rpRmMwbVI5/d2Pot2x5NR0WXVloA8M LehoYO50jgibwIV3D1kPFXLVwWc7UE7e/WfMPWlatCSpvd2epit8xS7Nn8vi+Ht0Xe SvJpL19Bqo+9lQ0MAOjB0qcKsoLVFBRGDIpewCV9d4EZy6+hAcE0kkRr/63Nix2+0V vJTR+hyO7F5wgikJ9cJNkO8fzyw9F5XN6AOuNrsVLcI7/WaokgtpFWbZzihIneT6P7 GEaGS3q5y9d7PX9M5Q6+ChQz0Puf5sxANMYOmIel6AUM45UKABKOPLwOxS+/3qRG/b DYFdFxtw+738w== Message-ID: <04a905af-f19e-4595-b8d7-e3c627f140bd@kernel.org> Date: Tue, 21 Apr 2026 16:07:51 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH RFC v2 17/18] mm: add free_frozen_pages_hint and put_page_hint APIs To: "Michael S. Tsirkin" Cc: linux-kernel@vger.kernel.org, Andrew Morton , Vlastimil Babka , Brendan Jackman , Michal Hocko , Suren Baghdasaryan , Jason Wang , Andrea Arcangeli , linux-mm@kvack.org, virtualization@lists.linux.dev, Lorenzo Stoakes , "Liam R. Howlett" , Mike Rapoport , Johannes Weiner , Zi Yan , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu References: <5f76af6e-9818-42ea-a305-c0fc1d920dca@kernel.org> <20260421091546-mutt-send-email-mst@kernel.org> <2a41dd0c-7ad8-4d34-8bab-a713e16c3b29@kernel.org> <20260421094049-mutt-send-email-mst@kernel.org> 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: <20260421094049-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Stat-Signature: d1mhbh6nr3anownxtd7cntd4hibi3b75 X-Rspamd-Queue-Id: 918111C0004 X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1776780481-543091 X-HE-Meta: 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 FKj7Ketl UtUqwuLoWkHSxFuhysHy3NgtAILldGFjLN0vCxst6l84o+yLt0b1IkGypZaQ3turgHMMWsCWItNZ0cN2Q292JmOPNuj1ntih8/V0cp30bV6XZlxGlpVpW9peTXGp/mKrYkUz6cprMYWD2MXuOvuyuoqS7pCHi/AhgbmpVlKGCtLACa/xbqvLiZv5AjeX+jhZ6AkjTY/Ts8//6QyDp1ETu5JPciFfSINDlDIThw5MhaL2fh79yC6tbzyZ+FeHNMzoNiInytBslGEpP///6waNIxzX9nAu6M82jWlzItfJ2RkF5H5GGDEcZWTPiJg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 4/21/26 15:44, Michael S. Tsirkin wrote: > On Tue, Apr 21, 2026 at 03:30:53PM +0200, David Hildenbrand (Arm) wrote: >> On 4/21/26 15:16, Michael S. Tsirkin wrote: >>> >>> We can - it's a dependency of the balloon deflate, which you asked >>> me to implement. I'm more interested in reporting, myself. >> >> Just to be clear, I said: >> >> "I'd assume ordinary inflating+deflating of the balloon would also end >> up with pre-zeroed pages. We'd just need a (mm/balloon.c -specific) >> interface to tell the buddy that the pages are zeroed." >> >> So while I think there will be value in that in the futur once we >> figure out a clean interface, I don't recall asking you to implement that? > > > Right. you also said: > > Not blocking, but I don't want something that is too coupled to > free-page reporting optimizations in the buddy. The comment above > MAGIC_PAGE_ZEROED triggered my reaction. > > so I interpreted this as meaning "it's nice to have (not blocking), but > you either need to implement this to demonstrate that indeed, it is not > too coupled, or prove in some other way that it is not too coupled". Then there was a misunderstanding. I consider it future work and just want the internals to easily allow for such a use case :) -- Cheers, David