From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=pass header.oldest-pass=0 smtp.remote-ip=52.101.53.68 ARC-Seal: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=pass; t=1793326317; b=uz+zeHp2UP0+U5am1OQ/MyyLockSZq9zksiQC6sNnaP0GOY7qxR9tpRC8aW2Pr95I/sY nbiJ8Oyue0uFWxpFXRB9oBfCBb+MGoJEI883k6uJEbvKrzoUl5emazy/9KwdsYSfFCUWZ baHwEk6a4qPYbcV7SekMAoapXEqs9IWMUdaFsJMXfxS4cqmYd6ZvwFFPRVr3mtOeXk9SA uFmyI/9XvSA4kfGlBLUE6Od9xPnza0uJKmnEZTJx4GJEB4FznAVNufHShE2FbBKjQ/syV 6/S/gPuQeVHiOTWApjW+55YRb+Cc+wXkVyLTdIdLSpsFGlgey08gCbj6da8z0ccIThA== ARC-Message-Signature: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793326317; h=DMARC-Filter:DKIM-Signature:Received:Received:From:To:Cc:Subject: Date:X-Mailer:Message-ID:In-Reply-To:References:Content-Type: Content-Transfer-Encoding:X-MS-Reactions:X-ClientProxiedBy: MIME-Version:X-MS-PublicTrafficType:X-MS-TrafficTypeDiagnostic: X-MS-Office365-Filtering-Correlation-Id:X-MS-Exchange-SenderADCheck: X-MS-Exchange-AntiSpam-Relay:X-Microsoft-Antispam: X-Microsoft-Antispam-Message-Info:X-Forefront-Antispam-Report: X-MS-Exchange-AntiSpam-MessageData-ChunkCount: X-MS-Exchange-AntiSpam-MessageData-0:X-OriginatorOrg: X-MS-Exchange-CrossTenant-Network-Message-Id: X-MS-Exchange-CrossTenant-AuthSource:X-MS-Exchange-CrossTenant-AuthAs: X-MS-Exchange-CrossTenant-OriginalArrivalTime: X-MS-Exchange-CrossTenant-FromEntityHeader: X-MS-Exchange-CrossTenant-Id:X-MS-Exchange-CrossTenant-MailboxType: X-MS-Exchange-CrossTenant-UserPrincipalName: X-MS-Exchange-Transport-CrossTenantHeadersStamped; bh=h+M4IRdbwygilqXWz4qb1mV9JQrGyhdpMRDLeQaCy20=; b=q1F6qSUDrmqvMu+kqROBx9MFQlq4Tv9esOEaTOgvPAsOMKwXu7+WHcQJC3NGwBmuMTtn ZuNIoR0SpN9YX/pC9pTTrPYkEsLKPpBixy21J/rCiL7NfRN5D7hB+FMEiAaH0kNdtFZkd lXlUMnhQfOcVPc0Yzu7YRcdmGyiY3DxEYJ1xe3fDg7bfamuKDUUuMtzVqY7ONl+2ekbnG tHVt+JsX22aNZCmBeSFDbAThM2YK2PDyGLfyPKl4QwjIQ794eg14Jt0pNcchpW5pRXbZb drxXHqt41r/x0Iiq/os5ahGlHtStMVZSllQHfP0Ap7VHuuPFywM9CLZQgCeXo1vuKEA== ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass header.d=Nvidia.com header.i=@Nvidia.com header.a=rsa-sha256 header.s=selector2 header.b=BUyDINjv; arc=pass header.oldest-pass=0 smtp.remote-ip=52.101.53.68 Received: from BL0PR03CU003.outbound.protection.outlook.com (mail-eastusazon11012068.outbound.protection.outlook.com [52.101.53.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (secp384r1) server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 90B22606A31A for ; Fri, 30 Oct 2026 02:11:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 90B22606A31A 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, unprotected) header.d=Nvidia.com header.i=@Nvidia.com header.a=rsa-sha256 header.s=selector2 header.b=BUyDINjv ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=QMW8ROJB5cCLcK/nnHA9kySBdSGR8R0BQKkYsoqBIKri+SZ+7BfVTrptwiD65/Reawt7hfYVs4KupxjqlulW0ak0seqb351UJtesROKLTDr62R9RUazKvf68wqy2u6yk0YcPplnCh35PGOED/izO/YILEAIdDhBBL6MlRdeA5XaT6LkWjz2bh8OViMUtgcdwR02Oi11RIQ1e6wVg0gBpHMYyQEde8LzZKhThVb6KZqwzinOPjmQ7zOAIn4iJk0a8kAToceoNVMYPi5QIxNWimA5YN2cUuYeNo1v9SMSBbMAee9mlPuERcPjMGSGdQTtXk8nbtXNq7/SUsqfRi+ljOQ== 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=h+M4IRdbwygilqXWz4qb1mV9JQrGyhdpMRDLeQaCy20=; b=xx1F7iuBYEf8/L7rWYcA5LinxQVk81wF98vo4NgIcc/okCrUGHRfSMGCxJtRHVeOtYkoWBilivUC6gzwE51/y8D9i1S1W/l+FLf4ZgrQNL2ASHY9vjCjZnHxHVB+EchS1q8OaL8nZYogM2FpYWy8b4SiE3M7LUVX8y21DRmETKpzYWVwCi866aGAwKMJqbSWZtHiRhK1xqYgE2iveE+17f+RdPj+gjjWydTgi1qw60yKV20iWW+pxgt1Vgwe8z/BW4NDcuZwylCn+1a9W5drSWh2zmSRmbmHvkeRTFLKDrC7l48iEPdcyBmEpPmLO6gtD66nHWEcflcVaZiL+iXJ9Q== 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=h+M4IRdbwygilqXWz4qb1mV9JQrGyhdpMRDLeQaCy20=; b=BUyDINjv6jDVW7113XWXCP/XpQOBO2/qy5o6uC2AvCoy2op5QFaOV9bU1NGFxbJcApxUuPtLPDoxmr1hMQUW3rwp3WXMB3b3pj8Dhg6udFZEa7OGWWW1NPr//MAFk9XZt+BYht7qFVIR4zOsc2lhDRiVvjdSQNFWeGu0q+eoTEWXsKktfky94nckiW4nB/KQ+bUO4Bt0BULFOV5LuS2+odYvXVRk+tUEeKbV5jtKz0q9nMS0hjq44M4Rpe/vpeI1cQXbSiowFJFOqaOOioh+yPFa+6qu3hmtRcPp4upJPSrZ0qgsr6PLZxku/ryehKiR6A/jdn/aK5ob3cy+6xx70g== Authentication-Results: mx.microsoft.com 1; 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 LV2PR12MB6014.namprd12.prod.outlook.com (2603:10b6:408:170::18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.569.8; Fri, 30 Oct 2026 02:11:53 +0000 Received: from IA0PR12MB8374.namprd12.prod.outlook.com ([fe80::d85f:4c87:ae84:3f16]) by IA0PR12MB8374.namprd12.prod.outlook.com ([fe80::d85f:4c87:ae84:3f16%6]) with mapi id 15.21.0569.007; Fri, 30 Oct 2026 02:11:53 +0000 From: Zi Yan To: "Ritesh Harjani (IBM)" Cc: linux-mm@kvack.org, Andrew Morton , Madhavan Srinivasan , Venkat Rao Bagalkote , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, David Hildenbrand , Muchun Song , Baolin Wang , Pavithra Subject: Re: [PATCHv2] mm/huge_memory: set the mmu_gather page size in zap_huge_pud() Date: Thu, 29 Oct 2026 22:11:51 -0400 X-Mailer: MailMate (3.0r7032) Message-ID: <013E1BCB-AAEF-4F85-875E-B670739262A9@nvidia.com> In-Reply-To: <8b853e5f9f16145859407b28af654b0f79e12642.1793318297.git.ritesh.list@gmail.com> References: <8b853e5f9f16145859407b28af654b0f79e12642.1793318297.git.ritesh.list@gmail.com> Content-Type: text/plain Content-Transfer-Encoding: quoted-printable X-MS-Reactions: disallow X-ClientProxiedBy: MN2PR22CA0028.namprd22.prod.outlook.com (2603:10b6:208:238::33) To IA0PR12MB8374.namprd12.prod.outlook.com (2603:10b6:208:40e::7) X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: IA0PR12MB8374:EE_|LV2PR12MB6014:EE_ X-MS-Office365-Filtering-Correlation-Id: 3f97a4e8-af70-44dc-41be-08df362b2a66 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|23010399003|7416014|376014|18002099003|6133799003|22082099003|56012099006|11063799006|261026140227099003|261026121527099003|10067099003|261021121427099003|261009223027099003|261028144727099003|261022105027099003|260925021911599003|260925022911599003|260925021311599003; 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)(1800799024)(366016)(23010399003)(7416014)(376014)(18002099003)(6133799003)(22082099003)(56012099006)(11063799006)(261026140227099003)(261026121527099003)(10067099003)(261021121427099003)(261009223027099003)(261028144727099003)(261022105027099003)(260925021911599003)(260925022911599003)(260925021311599003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?NbyfDrrrY379cyHibzCk7dvsaZ/Z/4GAST3Sjj6eLTcREApTn7hua4wtownP?= =?us-ascii?Q?feY/OhEpnU3mJxx3gjvbpV5Cw5IltNgsQZV765K6dZmhX8DMQjZlPxaoss0I?= =?us-ascii?Q?sL+Cq3Xx6P6ERknJR+Y4cuE735/LtA9OAQ+4Cp+x4LhtEndeegjdyNOcrucE?= =?us-ascii?Q?SghNdFKMN5cuYj7qMt4mO0DtqiWag0WWg/XQQTMm9RNetWxU+mxM52fEqppj?= =?us-ascii?Q?YN7GXV0BxrfR/qIMp7mvnoTybOoyW6/cP816IXZTwFRSX8rPzFUA3bNHVr4w?= =?us-ascii?Q?jkYJkLu1o4b42vLUMBPkGuZvpg2VxvoEOPbZkm5v5FyCp/4+Ui32ihqZ2oVx?= =?us-ascii?Q?9uB+RbUqhBSRSHT0EttaguJKu1qunkebyD6QxcyKiVOVu16w13MSWg9wxFHX?= =?us-ascii?Q?4GMVKvJb6KlJI68YGQHM7skIX/C3hPXpolDaCJrc7JktT6LeHN5ixLRoru+U?= =?us-ascii?Q?nHieam1pdFYQhmx0Hk4ajAxC0sbSSC768f7FWLkVUG2Z2PVbDpIGyLg2czJG?= =?us-ascii?Q?UChkrX6G3C9aU02209GusSru30TBBGlZL4Lf/sB92B0PYi5657762Ui8WiJn?= =?us-ascii?Q?V/L6HNrEAVfUyabjRfEcA3yz9V6Ig3TcsMURIuA3RIhiGRdD9e+1AFfGs76t?= =?us-ascii?Q?zOYU/5n2/wAvXEzckYQN8+QizOL1FJ3QdxHXA0WodiQ8uJ+iAp1+gexcLNvm?= =?us-ascii?Q?WeNlKHEleseqXiT7nP/3jPqyX/AEggoBXf2ppgw6fQyEhN7XkrSsM9uZq4HA?= =?us-ascii?Q?guoRXthT+OhUkiBViQRlJxnnRoNmgctXNXhGf3Pntftmh9Sgq0uvAildPFyH?= =?us-ascii?Q?HxTFL31eMkPwsNcQvFJXXAoHj1EWhEPcqv1cGjeBHSWYeXFGXiCmlX9sJpuc?= =?us-ascii?Q?MtP6LOQ2xCBzfivj1BYf96t2L5eCuA7nT3fykwVZaXCrFXSCEzOWQ6fhg1v+?= =?us-ascii?Q?yUDOJf7Z/0BCz/1kfJYb9M6w4S1A5j+1ZD7E5z2UXmw3Nlcv36g0wuSk9xok?= =?us-ascii?Q?9Sq26VeZkIp2HAzYzjNx2mVYctzG/dojz1eYux/3PH8OuM6QttlGGpQN3/9S?= =?us-ascii?Q?nFiD9joVZCawO3tQWpOflntw3S6ymkEu7orwdmi9XKcFMMN35vq0a+BK3on6?= =?us-ascii?Q?Ulx913keXcUGt1cuzjXDKYnLiooQIIc0PvVi6FsZpyYybc0n6lnz2MDJwGAV?= =?us-ascii?Q?5pk01j7muXZGZl9Me8jLRJzr+DGqZWjK0IxqrzsLDJPxloR6SJlchjKRIa3X?= =?us-ascii?Q?kn7xlhe7NJiLjAPv5Rf/04pFvebywO0jE7jMMPGmgL+OLynySo30B2b5xRFt?= =?us-ascii?Q?oCvuSNpm+AJ1huJcBOpdiDTWyk7MLpB41XNaQ9jrLU3dLxjXtgzR1jlclLfw?= =?us-ascii?Q?Lj0RxPxvYIUxlF2G6B+Vw5+Sxu3aYvl5GBHAdAOOjUDtXFJ7MoCh0zHGhIPu?= =?us-ascii?Q?EqHQQjqXjM6vFTvhuL3mY0jkuWZ558SCpRKRuxrRSS2h2N3va3evWBzXUt+/?= =?us-ascii?Q?4LKUCz9glGZIV9zWX2ivkJo2qZmuKjfBwODuEQEmj2WNEo54wjdW1VWkocDc?= =?us-ascii?Q?+g9zllgFF4NEVVvN9x2Wu5P/iG1eSoMX11LGzIQYbR3m2D3oYM7ROg9L/+ER?= =?us-ascii?Q?/0AegLwJ3y3zeaiFSZlBmllddDCfTlA/Vdb62+nC/MAYhfX2q0ileQtbS4Wf?= =?us-ascii?Q?SBYNC3GsaNahvTgIlS0u0PaM6K1M3n1eFU68AGiuhsRUsulM?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 3f97a4e8-af70-44dc-41be-08df362b2a66 X-MS-Exchange-CrossTenant-AuthSource: IA0PR12MB8374.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Oct 2026 02:11:53.3831 (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: sIDj3auhxVU/CdraN77H5uFGbAOxVlWp0+9GzybCQB2gGaqLslqjNm+GBthj7+nR X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV2PR12MB6014 On 29 Oct 2026, at 20:07, Ritesh Harjani (IBM) wrote: > Unmapping a device-dax mapping with 1G alignment on powerpc radix kerne= l > built with CONFIG_DEBUG_VM triggers this warning on every munmap: > > WARNING: mm/mmu_gather.c:176 at __tlb_remove_folio_pages_size+0x38/= 0x230 > NIP [c00000000063d508] __tlb_remove_folio_pages_size+0x38/0x230 > LR [c0000000006fb688] zap_huge_pud+0x1b8/0x2d0 > Call Trace: > zap_huge_pud+0x170/0x2d0 (unreliable) > __zap_vma_range+0x1604/0x1e20 > unmap_vmas+0xa0/0x1f0 > unmap_region+0xb0/0x130 > vms_complete_munmap_vmas+0x120/0x310 > do_vmi_align_munmap+0x1ec/0x240 > __vm_munmap+0x148/0x220 > sys_munmap+0x28/0x40 > > To trigger this - it is enough to mmap() /dev/dax0.0, touch the first > byte so that the whole 1G is mapped by a single PUD and then munmap() > it. > > PowerPC needs MMU_GATHER_PAGE_SIZE in which mmu_gather needs to record > the page size for which tlb flush is needed. zap_huge_pmd(), > zap_pte_range(), change_huge_pud() etc all do this already. However, > since commit: > dbe54153296d ("mm/huge_memory: add vmf_insert_folio_pud()") > > a device-dax PUD maps a real folio and zap_huge_pud() now hands it to > tlb_remove_page_size(tlb, page, HPAGE_PUD_SIZE). At that point > tlb->page_size is still whatever the previous user left behind, which i= s > 0 for the fresh gather set up by munmap() and so the check fires. > > Fix this in the same way like how other similar paths do. > > Fixes: dbe54153296d0 ("mm/huge_memory: add vmf_insert_folio_pud()") > Reported-by: Pavithra > Signed-off-by: Ritesh Harjani (IBM) > --- > [v1]->v2: > =3D=3D=3D=3D=3D=3D=3D=3D=3D > - Split the 2 part patch series. Patch-1 is now superseded by a differe= nt patch > from Muchun which he already posted [2]. > - No difference in this patch from v1. > > [v1]: https://lore.kernel.org/all/97f85592bb78a273be8519e6897e7f9b9bd31= 469.1793070429.git.ritesh.list@gmail.com/ > [2]: https://lore.kernel.org/all/20261029063601.1961415-1-songmuchun@by= tedance.com/ > > mm/huge_memory.c | 2 ++ > 1 file changed, 2 insertions(+) > Makes sense. Thanks. Acked-by: Zi Yan Best Regards, Yan, Zi