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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BCB33C56205 for ; Wed, 5 Aug 2026 19:35:48 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6363210EFC0; Wed, 5 Aug 2026 19:35:45 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="aFXJ7nl8"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6F1EE10E0FB; Wed, 5 Aug 2026 19:35:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1785958543; x=1817494543; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=0YG7iyYcbF3G1EFKh9ioNjadG3W1OhFnqKUemvuHbQY=; b=aFXJ7nl8Xmg/f4pCVnXKOv7sXt4lReF8lalt/qP/NJB1GLFaD1E/Ee0M 77FxEdEW6ED11ZWvmeW9/N3jCf/pnzfvNqMX6YUkeh5TLHM6e129WVbAT JLWdrx2lt6QzKT7t7KefTmqQBmdcGTJ2oW4gpXEamLPgRdIAbTbhAcUYG LXX2Bbe9Q7XXL4ML91YIhM7MFPYJqsBGNCUV2+q1aU3GnCfgqEppplu4j KddoZM1nS95jjSXqm96W+GEadsKDLGRT+jALzSsHMujNU4ISrHe5Q5x3o iEl2OPBjvoqW19ec5H7zvVpE4h6uBL1sM22bLC3shLOXLfPZ0jdQfJNhs g==; X-CSE-ConnectionGUID: 9Vxu77AJQIKmzxOyR45zOw== X-CSE-MsgGUID: ga2vXmbKSJaLLooI7GYldw== X-IronPort-AV: E=McAfee;i="6800,10657,11866"; a="109332919" X-IronPort-AV: E=Sophos;i="6.25,207,1779174000"; d="scan'208";a="109332919" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Aug 2026 12:35:42 -0700 X-CSE-ConnectionGUID: +IlgXOyXTU+bAoeSzcnfsg== X-CSE-MsgGUID: aH+F8fM8RHmiW/7pNd/qeA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,207,1779174000"; d="scan'208";a="285263519" Received: from gsse-cloud1.jf.intel.com ([10.54.39.91]) by fmviesa002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Aug 2026 12:35:42 -0700 From: Matthew Brost To: intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Sashiko , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Zi Yan , Baolin Wang , "Liam R . Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Balbir Singh , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= , Francois Dugast , stable@vger.kernel.org Subject: [PATCH v2 1/5] mm/migrate_device: Clear MIGRATE_PFN_MIGRATE on all sub-folios of a split THP Date: Wed, 5 Aug 2026 12:35:32 -0700 Message-Id: <20260805193536.3756457-2-matthew.brost@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260805193536.3756457-1-matthew.brost@intel.com> References: <20260805193536.3756457-1-matthew.brost@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" migrate_vma_split_unmapped_folio() propagates MIGRATE_PFN_MIGRATE from the head entry to all HPAGE_PMD_NR entries of src_pfns[]. The two bailouts below it in __migrate_device_pages() only cleared the head, and the "next" label then advances by @nr, so the tails keep the flag and a valid destination without ever going through folio_migrate_mapping(). migrate_vma_finalize() then maps unpopulated destination folios into userspace. Clear the flag across the whole @nr range at both bailouts. Reported-by: Sashiko Fixes: 4265d67e405a ("mm/migrate_device: add THP splitting during migration") Cc: Andrew Morton Cc: David Hildenbrand Cc: Lorenzo Stoakes Cc: Zi Yan Cc: Baolin Wang Cc: Liam R. Howlett Cc: Nico Pache Cc: Ryan Roberts Cc: Dev Jain Cc: Barry Song Cc: Lance Yang Cc: Usama Arif Cc: Joshua Hahn Cc: Rakie Kim Cc: Byungchul Park Cc: Gregory Price Cc: Ying Huang Cc: Alistair Popple Cc: Balbir Singh Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie Cc: Simona Vetter Cc: Thomas Hellström Cc: Francois Dugast Cc: dri-devel@lists.freedesktop.org Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Assisted-by: GitHub_Copilot:claude-opus-5 Signed-off-by: Matthew Brost --- mm/migrate_device.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/mm/migrate_device.c b/mm/migrate_device.c index 908d2d4ec43a..d37a96cc6335 100644 --- a/mm/migrate_device.c +++ b/mm/migrate_device.c @@ -1199,10 +1199,14 @@ static void __migrate_device_pages(unsigned long *src_pfns, * device private or coherent memory. * * Try to get rid of swap cache if possible. + * + * @folio may have been split into @nr folios + * above, so clear all of them. */ if (!folio_test_anon(folio) || !folio_free_swap(folio)) { - src_pfns[i] &= ~MIGRATE_PFN_MIGRATE; + for (j = 0; j < nr && i + j < npages; j++) + src_pfns[i+j] &= ~MIGRATE_PFN_MIGRATE; goto next; } } @@ -1210,7 +1214,8 @@ static void __migrate_device_pages(unsigned long *src_pfns, /* * Other types of ZONE_DEVICE page are not supported. */ - src_pfns[i] &= ~MIGRATE_PFN_MIGRATE; + for (j = 0; j < nr && i + j < npages; j++) + src_pfns[i+j] &= ~MIGRATE_PFN_MIGRATE; goto next; } -- 2.34.1