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 10E0AD2ECEC for ; Mon, 19 Jan 2026 22:25:22 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7CB006B02FD; Mon, 19 Jan 2026 17:25:21 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 777FE6B02FE; Mon, 19 Jan 2026 17:25:21 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 67AD46B02FF; Mon, 19 Jan 2026 17:25:21 -0500 (EST) 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 541E86B02FD for ; Mon, 19 Jan 2026 17:25:21 -0500 (EST) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 13E8357F00 for ; Mon, 19 Jan 2026 22:25:21 +0000 (UTC) X-FDA: 84350145642.05.4BF65DA Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf29.hostedemail.com (Postfix) with ESMTP id 5194B120006 for ; Mon, 19 Jan 2026 22:25:19 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=WmGzBhmm; spf=pass (imf29.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=1768861519; 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=4qS23eudvVzt1ADpbBF5gUBwHId5bYBqcp3NoGL7nts=; b=rlVO7P710k6/cGW1yk+lmvkZrbM2MZoJnFg5uS53Ede6tB2OjbEpQlJU/U7hrhLts4Ai+P z6BsEcvmZ4ISaNCWZQQFh4NLEAITnxHc9Gki5rVaCP3YxZuflyF4khnaMh4dmcw9VoJjLR 0q3lhT1PcNreEa3gI8qak1g/K20uYjM= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=WmGzBhmm; spf=pass (imf29.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=1768861519; a=rsa-sha256; cv=none; b=IGOxtUsXxCdrN/HlVrrjKwfT7Sw1OHcgNddfpk8Ul7RXszJ6ahl8TU8FPd1NVwwziqfp3r /3Na+BXIefDQINptDFzaz88y3KfFK5rxoEacAfdLv5uqD6NZ7xDqTzIGNTMPam8E64r/LU PVMeggGxTK5K6Lr5jWlWU/2fkI4Zv20= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 662B8600CB; Mon, 19 Jan 2026 22:25:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 107A2C116C6; Mon, 19 Jan 2026 22:25:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768861518; bh=FAhDAb0u3mhKiWuTRu6Dbpf4eWwLQGrJyZKWWKJe3go=; h=Date:Subject:From:To:Cc:References:In-Reply-To:From; b=WmGzBhmmvAQt5l5PbvA8zaQPDgIuoNJskhe2N4F8kWZBPAyFdiTaUh/0OAgssMGd2 wmR9MvAzNiAjh0x3J/R2+upFQVVUoOV7ZvNeRcDxof0gAxpDlGIU3XZhrWxn+d/rXR VSsdH/bnurWZxA7coDt74Hi4pzAMr1cK42OTzJq3HDfk2DF8vlS81Gq3/Pi3QNBgHY 71HZGZJlIPV0hfC/5Y0hpCXejNXp82PxIRri2qQvnH84xKv+ovHC48pyIa7PUaN2V6 kLD7UHibuKDHv2Y5KmPkLd3dt6r4MamPb71DAKpl4k2EJN4VhbZHHfRJTm8doogByw BcwE41Ikj3k9A== Message-ID: <7cbea892-0ccd-4132-af55-d72abd704d6c@kernel.org> Date: Mon, 19 Jan 2026 23:25:10 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 04/23] mm/balloon_compaction: centralize basic page migration handling From: "David Hildenbrand (Red Hat)" To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, Broadcom internal kernel review list , linux-doc@vger.kernel.org, virtualization@lists.linux.dev, Andrew Morton , Oscar Salvador , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jonathan Corbet , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Arnd Bergmann , Greg Kroah-Hartman , Jerrin Shaji George , "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , =?UTF-8?Q?Eugenio_P=C3=A9rez?= , Zi Yan References: <20260115092015.3928975-1-david@kernel.org> <20260115092015.3928975-5-david@kernel.org> 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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAa2VybmVsLm9yZz7CwY0EEwEIADcWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCaKYhwAIbAwUJJlgIpAILCQQVCgkIAhYCAh4FAheAAAoJEE3eEPcA/4Naa5EP/3a1 9sgS9m7oiR0uenlj+C6kkIKlpWKRfGH/WvtFaHr/y06TKnWn6cMOZzJQ+8S39GOteyCCGADh 6ceBx1KPf6/AvMktnGETDTqZ0N9roR4/aEPSMt8kHu/GKR3gtPwzfosX2NgqXNmA7ErU4puf zica1DAmTvx44LOYjvBV24JQG99bZ5Bm2gTDjGXV15/X159CpS6Tc2e3KvYfnfRvezD+alhF XIym8OvvGMeo97BCHpX88pHVIfBg2g2JogR6f0PAJtHGYz6M/9YMxyUShJfo0Df1SOMAbU1Q Op0Ij4PlFCC64rovjH38ly0xfRZH37DZs6kP0jOj4QdExdaXcTILKJFIB3wWXWsqLbtJVgjR YhOrPokd6mDA3gAque7481KkpKM4JraOEELg8pF6eRb3KcAwPRekvf/nYVIbOVyT9lXD5mJn IZUY0LwZsFN0YhGhQJ8xronZy0A59faGBMuVnVb3oy2S0fO1y/r53IeUDTF1wCYF+fM5zo14 5L8mE1GsDJ7FNLj5eSDu/qdZIKqzfY0/l0SAUAAt5yYYejKuii4kfTyLDF/j4LyYZD1QzxLC MjQl36IEcmDTMznLf0/JvCHlxTYZsF0OjWWj1ATRMk41/Q+PX07XQlRCRcE13a8neEz3F6we 08oWh2DnC4AXKbP+kuD9ZP6+5+x1H1zEzsFNBFXLn5EBEADn1959INH2cwYJv0tsxf5MUCgh Cj/CA/lc/LMthqQ773gauB9mN+F1rE9cyyXb6jyOGn+GUjMbnq1o121Vm0+neKHUCBtHyseB fDXHA6m4B3mUTWo13nid0e4AM71r0DS8+KYh6zvweLX/LL5kQS9GQeT+QNroXcC1NzWbitts 6TZ+IrPOwT1hfB4WNC+X2n4AzDqp3+ILiVST2DT4VBc11Gz6jijpC/KI5Al8ZDhRwG47LUiu Qmt3yqrmN63V9wzaPhC+xbwIsNZlLUvuRnmBPkTJwwrFRZvwu5GPHNndBjVpAfaSTOfppyKB Tccu2AXJXWAE1Xjh6GOC8mlFjZwLxWFqdPHR1n2aPVgoiTLk34LR/bXO+e0GpzFXT7enwyvF FFyAS0Nk1q/7EChPcbRbhJqEBpRNZemxmg55zC3GLvgLKd5A09MOM2BrMea+l0FUR+PuTenh 2YmnmLRTro6eZ/qYwWkCu8FFIw4pT0OUDMyLgi+GI1aMpVogTZJ70FgV0pUAlpmrzk/bLbRk F3TwgucpyPtcpmQtTkWSgDS50QG9DR/1As3LLLcNkwJBZzBG6PWbvcOyrwMQUF1nl4SSPV0L LH63+BrrHasfJzxKXzqgrW28CTAE2x8qi7e/6M/+XXhrsMYG+uaViM7n2je3qKe7ofum3s4v q7oFCPsOgwARAQABwsF8BBgBCAAmAhsMFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAmic2qsF CSZYCKEACgkQTd4Q9wD/g1oq0xAAsAnw/OmsERdtdwRfAMpC74/++2wh9RvVQ0x8xXvoGJwZ rk0Jmck1ABIM//5sWDo7eDHk1uEcc95pbP9XGU6ZgeiQeh06+0vRYILwDk8Q/y06TrTb1n4n 7FRwyskKU1UWnNW86lvWUJuGPABXjrkfL41RJttSJHF3M1C0u2BnM5VnDuPFQKzhRRktBMK4 GkWBvXlsHFhn8Ev0xvPE/G99RAg9ufNAxyq2lSzbUIwrY918KHlziBKwNyLoPn9kgHD3hRBa Yakz87WKUZd17ZnPMZiXriCWZxwPx7zs6cSAqcfcVucmdPiIlyG1K/HIk2LX63T6oO2Libzz 7/0i4+oIpvpK2X6zZ2cu0k2uNcEYm2xAb+xGmqwnPnHX/ac8lJEyzH3lh+pt2slI4VcPNnz+ vzYeBAS1S+VJc1pcJr3l7PRSQ4bv5sObZvezRdqEFB4tUIfSbDdEBCCvvEMBgoisDB8ceYxO cFAM8nBWrEmNU2vvIGJzjJ/NVYYIY0TgOc5bS9wh6jKHL2+chrfDW5neLJjY2x3snF8q7U9G EIbBfNHDlOV8SyhEjtX0DyKxQKioTYPOHcW9gdV5fhSz5tEv+ipqt4kIgWqBgzK8ePtDTqRM qZq457g1/SXSoSQi4jN+gsneqvlTJdzaEu1bJP0iv6ViVf15+qHuY5iojCz8fa0= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 5194B120006 X-Stat-Signature: i9qxeriro1tj3amkc8bmydqmpco9cwmg X-HE-Tag: 1768861519-351218 X-HE-Meta: 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 rGrfq7l1 c7nfNMUQZ1FBq3y5dAZmWK2uyVCCbj+9QgWNc2zOKmtsx7opZjVPnGZiUIeyhl1kCgxFZLvkNWL+EOejl5y6P39rvl7FvJ1rxGxy+EPVXas+xgMhPh0kAVdXQuLmY+1O+1IfMLy1xcetwstixOIzFzHRHh403EpDY/5k3aGwMoA5BrEzk2pOKyVOMZvDYx8zaYx4s7y6UHhi7a13/bHQMvh5CnaVU0dh0XYQsq6ylI/CwfDD2LrdgBh2V26oCVcAzzJ7WMeg2LUq/ZOvveAt04dHgL81iEj4yra/zyjKtfWLtu19nJnRHwYq4A8EA2ELH7qMYchTEUyT+vps= 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 1/19/26 23:22, David Hildenbrand (Red Hat) wrote: > On 1/15/26 10:19, David Hildenbrand (Red Hat) wrote: >> Let's update the balloon page references, the balloon page list, the >> BALLOON_MIGRATE counter and the isolated-pages counter in >> balloon_page_migrate(), after letting the balloon->migratepage() >> callback deal with the actual inflation+deflation. >> >> Note that we now perform the balloon list modifications outside of any >> implementation-specific locks: which is fine, there is nothing special >> about these page actions that the lock would be protecting. >> >> The old page is already no longer in the list (isolated) and the new page >> is not yet in the list. >> >> Let's use -ENOENT to communicate the special "inflation of new page >> failed after already deflating the old page" to balloon_page_migrate() so >> it can handle it accordingly. >> >> While at it, rename balloon->b_dev_info to make it match the other >> functions. Also, drop the comment above balloon_page_migrate(), which >> seems unnecessary. >> >> Signed-off-by: David Hildenbrand (Red Hat) >> --- > > Andrew, the following on top: Ah no, I'll rather resend the whole thing, as it creates some conflicts in the other patches. -- Cheers David