From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from PH7PR06CU001.outbound.protection.outlook.com (mail-westus3azon11010030.outbound.protection.outlook.com [52.101.201.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A4B233C13F9; Thu, 16 Jul 2026 21:13:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.201.30 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784236398; cv=fail; b=OFeUnhxNNlVXleVfzMdg/IjC1cjUFLx3Rek7z0J7LrfpBSanGDN/VEVSuKUfrgNpZVQlxYqOxFSpjj0qPobcd3ZsYmkcld/vIaycBkaUgO88lKVRerCeRPEIvONhDFo/mx0D6VSGWFJV06jx55fHLCwKJ9Kn55PaPJc/Nqpgi8I= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784236398; c=relaxed/simple; bh=yZ7+X44404eWeAkucu9lpQsImuDdD7aVIAcuV3ALKN4=; h=Content-Type:Date:Message-Id:Cc:To:From:Subject:References: In-Reply-To:MIME-Version; b=QAGKvJaR1Xo94Ft+vYZslQoA2t+6paeOMPoNJTy1x2qUkPO/YdX0tsUNxeg6xvHKj9dtMDoWT3ODhQTw+XkBvLr5pGEAdfwu6/6RLDs+FO+kNbBBU9GCYn5BDr6Y3BW5EQDYmatyi9A52HxzSNoq/CqkM428t9yNIv8ccxd4lcg= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=DYWEPL2S; arc=fail smtp.client-ip=52.101.201.30 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="DYWEPL2S" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=aqc3EFpBe88t8ZOcd7IkI8jLzaWwmDHihKSSiKqw2WR4qV+N3y2d/6A/ydC3oUoeJUUo56OvW0JrSh95W9Dn7Cw1fG3wI0pnjzz5DsjHLc/2nZJMSa6Yrr2g4A1ltDhBzFrwc5xC0jgQy0qY4xevubD/Td3SGAr1stHaRmfEEnXaqGz9SKWQQNxUfTh977TkOmqIsXxvEuQnFcsHuQYh0cWeCvKDz46/hGhC6aDSqMtxWPDl8VN3pWuaaaXmWfCjodQA0fex+7DwRFwTwAV/ZNGHrZmPLIfCcXs8fToOF1AhRFX6sVc/vC5sKLnkELq9FIqCE/KCEaY4jNvM48YRiQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=bA8jHUfmeiY9ODIQ+oQrdalET7uV5CJGJAq9giAeSTw=; b=jI+TRtOUNzsGNczJFMfp2j3pXdDiuvpIN9Ymi/5Qz6jdW37ZdptbZt4l+tY8FJQHteuWuM8PBNhQfLkol1mqZIWaV+lB72XBO91L6jEuI91/YRfb9APsCQpRW3Uyk1rHAAuG+5TG+AzO9zrWuO0DoE7Dsvuuh14BAAznOYPf8ZU1y8dRMMS5NLgMh+0yWrbmMaduPsmt3tUn2g2ZQm40KC59PEhL3UE+zn3BBHlWSUvmvQdmwA33qzQrwAaQHY+8hs1E9s/2lo8If1d3MuIpDiDkdb68iSs0tL+KmaNposIuvd/P6XhyEz9zqN1TguHdsp7YmQLtvhMDf43CcZGxPQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=bA8jHUfmeiY9ODIQ+oQrdalET7uV5CJGJAq9giAeSTw=; b=DYWEPL2SoDLNnCthPvmWquXvu2Uz+Nbiubr7CGDFfgqJE7HZ+gJNzkBleRWF+I7MwNcC4FBd3s99uuhVUAQktrvD/7N/FAg7Tp95z8oZHWMPi8Y/4id5yRTGyBQfMq+bNPr12+ojam5zL6jfUndy3XvTi/RE0CwSaOAwv67+2uJtJG+7PFL6aU1/tXNwUYOr/Ak7nOm2FilImoAaQFiWRUFEPGqlnTr1rBYVl5K29yARar+T1UAutkyKvsmIPdBMp9O0DWMKWVfZMw0qPdSmNXcURv6YiO/7XBIK0sSRDNfgfntZlR2AiRIjlvOtLCEdr6xCMmYZ88O0tqGKoTISrw== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from IA0PR12MB8374.namprd12.prod.outlook.com (2603:10b6:208:40e::7) by DS0PR12MB9424.namprd12.prod.outlook.com (2603:10b6:8:1b4::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.223.12; Thu, 16 Jul 2026 21:13:07 +0000 Received: from IA0PR12MB8374.namprd12.prod.outlook.com ([fe80::d85f:4c87:ae84:3f16]) by IA0PR12MB8374.namprd12.prod.outlook.com ([fe80::d85f:4c87:ae84:3f16%5]) with mapi id 15.21.0223.008; Thu, 16 Jul 2026 21:13:07 +0000 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Thu, 16 Jul 2026 17:13:06 -0400 Message-Id: Cc: , , To: "David Hildenbrand (Arm)" , "Dave Hansen" , "Andy Lutomirski" , "Peter Zijlstra" , "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , , "H. Peter Anvin" , "Andrew Morton" , "Lorenzo Stoakes" , "Liam R. Howlett" , "Vlastimil Babka" , "Mike Rapoport" , "Suren Baghdasaryan" , "Michal Hocko" , "Brendan Jackman" , "Johannes Weiner" , "Alexander Gordeev" , "Gerald Schaefer" , "Heiko Carstens" , "Vasily Gorbik" , "Christian Borntraeger" , "Sven Schnelle" , "Muchun Song" , "Oscar Salvador" From: "Zi Yan" Subject: Re: [PATCH v2 02/10] mm: provide free_reserved_pages(), removing x86 variant X-Mailer: aerc 0.21.0 References: <20260716-bootmem_info_part2-v2-0-4afc76c73d61@kernel.org> <20260716-bootmem_info_part2-v2-2-4afc76c73d61@kernel.org> In-Reply-To: <20260716-bootmem_info_part2-v2-2-4afc76c73d61@kernel.org> X-ClientProxiedBy: MN0PR05CA0011.namprd05.prod.outlook.com (2603:10b6:208:52c::17) To IA0PR12MB8374.namprd12.prod.outlook.com (2603:10b6:208:40e::7) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: IA0PR12MB8374:EE_|DS0PR12MB9424:EE_ X-MS-Office365-Filtering-Correlation-Id: 1341bcd9-2a73-42bd-e7bb-08dee37f0862 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|23010399003|366016|1800799024|921020|10067099003|11063799006|4143699003|22082099003|18002099003|56012099006; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:IA0PR12MB8374.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(7416014)(376014)(23010399003)(366016)(1800799024)(921020)(10067099003)(11063799006)(4143699003)(22082099003)(18002099003)(56012099006);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?T0NNS3VPQWljSUhNcnlzQk5MS3ZpK0ZSTnpaWVRTTXIvS2RhMFhIc1N3YmEr?= =?utf-8?B?enF1SXF2YTdheVY1N0VOdTFmUVJpcDR1V0ExRU8zVndtbGlGa2xudTBITU94?= =?utf-8?B?Ylk1T05DVS8vK1g1RGJUT3FnMS8xTVRyNXlEYVdPRkpVKzdvNVRhS2M5YU12?= =?utf-8?B?M2JIVDZBOUpVR3Z2YndSV2kxY2VQT3dEWUNvTXhPelNEbXRHajRubTBjZFhB?= =?utf-8?B?YXdQckFEZmhJcGRwcG5GVlN4bGp6WGxpdWpWckpCK1dDQ2NuZzN1cXQrN0xn?= =?utf-8?B?eGs1Rkg4N3V4U1VoeWNtWFFDZkZNQVRNTC9OM0dvU1R2Uko4bXgzRGJkTGg1?= =?utf-8?B?dzJsU2lEUXV4ZlVyd0RJNGRVR3pSR0xRbGJPRWtRN0lnZ3g0OVgydy9ia3Zs?= =?utf-8?B?aFQ3aGlzeGQ2MmZ3R0dsVEUwb29xa3UvdkxsY3JwTHFGZ1oxcmNBQ2hTRlhW?= =?utf-8?B?QTh4QXV3ZDdUOGRYZytjUWM5ZC9ibmdXTTliVy91eHR0Y0JEMDJya0JNN1pa?= =?utf-8?B?R2I4T2I4UVAyZW9sNDc3UnJlSGFtbldOeEVZczhWVGFMY0d1SkFFeVFEVmlv?= =?utf-8?B?TEVkSFZTWSt0WmxLMVczbmdhOEozRjZnS2p3SGh5dnBFRjdLT1dKUElkTXlC?= =?utf-8?B?UUJaU2l1Z28vTHA3N2ZXdzh3YnYxWEVQZnowenNLTk5LbU1ScGNIdm5ZVXM3?= =?utf-8?B?RDlmK0tVNWYwQ2R0blBDRGpndVpNdEwvV0V1Zjd6N2xpSkFVUmgxR1dUSFlL?= =?utf-8?B?dkk5SnVJQ3RJMnk4ZmtXdTdUS2VEc2RTM2Q3bDMxTUpQTGtBOWErVUgzaXBZ?= =?utf-8?B?Mm11aklVOFFyOEVpUDVkSk9qb0ZYV1BQMkpyNEVBMXczOWwzZXdmamlaVVdm?= =?utf-8?B?L1lIeDdSamx2dmswK3VKa0lIaW9OV2ZIM3oxREloaDJCZ1R2MVpXWnF0T1lK?= =?utf-8?B?Nmd2K01CMFo5dVlVMDdlVFZFQ2F6UDBGSTVHZlZ6TG4xelpsdVZjeHB3YVcx?= =?utf-8?B?Ulp4TTZxV3pFN21wYlRLTVVQMHF5U1JvYVJTL3ZndUVvdHlwSTRPc2p6VStC?= =?utf-8?B?N004NXBhMW1kTWxjQVUwR2RRQVBqODFpSVpGMlMvY3BUUmEvNU1YZEZIVkF4?= =?utf-8?B?VEU2K09aS2ozMHRmamcrT2ptWVc5MWROcHFxRjE4OTVvVGxOc0NkSDBkT2kz?= =?utf-8?B?Vmo4Q0NscDFscHpkclR3NnZJeUw0N3A2YlNOdGdraTJiVGsrVEJadUFvUkk0?= =?utf-8?B?TjU3d0JMOURiUzk1aDAvT05TVUlQRis4Ti9laHE4WjVFYnhLS2pud3M5czZo?= =?utf-8?B?NHhLOUZ1UFk5OWRKTHNJcHFZR05nTktMWmtaQVhSMjdUaWtOcnhHRlBQYW1U?= =?utf-8?B?WkRzbTdtWWxpYTdEWlkxQVZ4MnF1V080cTVOQklOT094VUV2OVZNOWdXK2Ra?= =?utf-8?B?TDF6QkRxV1E0Z1AxSnc5N3N6UnFYTnJnMzJMcm8xZlpkTUVLYlV1eTBFMEsz?= =?utf-8?B?NHJMSDF4WE5VeGVzTlhrOUpRSEFmajFJOE83NS9Lc1hoamJCZWxYbmpTRi9Y?= =?utf-8?B?SzI0dWdYTDVHZElLUGdQK0pWNE9DNndhaXVvdm5XS2ZEb0pLb2NPNnAxWnRL?= =?utf-8?B?eWlIelMxNHRFL2o3NzRZdjEzZk5CTDhRdUR2VFl6dVBZU1pXTHpvbmcyNW5x?= =?utf-8?B?b3ZpY0pwei9DQkxhQ1BhMGIyMXcwSUdrVzRzRnFIN1hGdHRvMW5HQk9EM2No?= =?utf-8?B?K2ZMcGdEeUx5RE8vVUU1dUtJSEN2TGhaR0NJcTRKRUNKeWRqK0Y2Z0lVL01n?= =?utf-8?B?cExOV2FrTlRSc3hKTkdqcUNmejUwenlhK3pWY1R4Y09RK2FsbWREdDVxaVhJ?= =?utf-8?B?aUJhc09qQW93cENDbk5Lc2JibFRoY2R2SWNWaFhLWDgxN0RwVDg0Z25lMkNm?= =?utf-8?B?UG1UWUR5OUpIVFJ6c3R3ZEgvMGxEclZEL01WL2Y0dVlMUzZtdWxCczNUNi9p?= =?utf-8?B?R3hiZ2ZpNUQxQ0gzVzNEeE10U1pnOXN3TkNVUFcydGdJZFpTdHdSK213cmsz?= =?utf-8?B?cytHQkhaRVZhRkR1TVNGRlRyaHp0eWh0WmRlWFJNalFTZzlacGJ6dW40MDRx?= =?utf-8?B?ODE0V2RTVDltRm5PWlgzeit1Sk9Wd3FQeUYvSkx5MUtPcDRSNFg4bm4wSWt3?= =?utf-8?B?SEdnVVBTU29zR0NXRkl6NVNEM0tTd0RjUFBLWWNjQ1F4TUpGT0dIUklvekNi?= =?utf-8?B?bFI2YlMyRDQvdTdsejRQUmJSaWpaV2QxZlp2djFIZUl4bkk3TG50MGpHQUtE?= =?utf-8?Q?nBEU6kWdw05LT3MgnI?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 1341bcd9-2a73-42bd-e7bb-08dee37f0862 X-MS-Exchange-CrossTenant-AuthSource: IA0PR12MB8374.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 16 Jul 2026 21:13:07.5360 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 1miJ0rrYcqyX2erdQ0ze8URwLqkmJDCJzPzgj3xjNP8Rj6WSita2aoH3djC4XioK X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS0PR12MB9424 On Thu Jul 16, 2026 at 10:51 AM EDT, David Hildenbrand (Arm) wrote: > Let's extend free_reserved_page() in page_alloc.c to free_reserved_pages(= ), > dropping the custom x86 variant. The common-code variant will consume an > order, so adjust the x86 callers accordingly. > > Make free_reserved_pages() assume that we are freeing ordinary > high-order pages, just with the special "reserved" flavor. The target > use case for now is freeing vmemmap PMD pages. > > Set the refcount directly to 0 (instead of 1) and call > __free_frozen_pages(). Set the page count to 0 before clearing > PG_reserved, so someone checking PG_reserved (and not finding it set) > to then try grabbing a ref would not suddenly have that ref be dropped. > That is arguably cleaner and safer than the old way of doing it. > > Add some kerneldoc. Use a single adjust_managed_page_count() call. > > Reviewed-by: Mike Rapoport (Microsoft) > Reviewed-by: Muchun Song > Signed-off-by: David Hildenbrand (Arm) > --- > arch/x86/mm/init_64.c | 8 +------- > include/linux/mm.h | 8 ++++++-- > mm/page_alloc.c | 33 ++++++++++++++++++++++++++------- > 3 files changed, 33 insertions(+), 16 deletions(-) > LGTM. Reviewed-by: Zi Yan --=20 Best Regards, Yan, Zi