From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3D04E606E6D8 for ; Tue, 27 Oct 2026 15:47:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=UhCwhlHW Received: by kanga.kvack.org (Postfix) id 072986B07DB; Tue, 27 Oct 2026 11:47:03 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F17306B07DD; Tue, 27 Oct 2026 11:47:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DDE866B07DE; Tue, 27 Oct 2026 11:47:02 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id AA5876B07DB for ; Tue, 27 Oct 2026 11:47:02 -0400 (EDT) Received: from smtpin05.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 0422AA0947 for ; Tue, 27 Oct 2026 15:47:01 +0000 (UTC) X-FDA: 85368834684.05.3A6E34E Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf06.hostedemail.com (Postfix) with ESMTP id 55110180003 for ; Tue, 27 Oct 2026 15:47:00 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=UhCwhlHW; spf=pass (imf06.hostedemail.com: domain of vbabka@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=vbabka@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=1793116020; 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=seQJ0RkpYsv0DnDnr/texKmVDxEFVMoOUeLo6OCf//M=; b=dvStJpGc7ujdFRwr0Qw0iye6KAL2cXdwWiz1xiLa1HX6JE3NE53xiZmRRn9+TPQxhyHPfX Ad/mOR65ppyH8w5tBRZorn1bP7t5jtWxmUBFjWCIH3+jGlZMZc/QgCb55zw0QAEaWI8+Mo f1UMVwre2AxlEwhxKuMkJP6uqnJPnMM= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=UhCwhlHW; spf=pass (imf06.hostedemail.com: domain of vbabka@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=vbabka@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1793116020; b=U/R21NnIdHfS49kdxgAccM7pZdxvbxGw0nho6dIa4oyQw8IN66vcxqkw9U6XXXpoXVofGV vIZsqRuo8RJgf9Znx658PSjBKbagZEObDc6sZkBcn0UXRvH4LXm1AaSewFAzUlpPRy+ACj 6Ue1vcC9Lkj64ZdU7bU2AaTDla6Ty1s= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id A3CA743E65; Tue, 27 Oct 2026 15:46:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 86E6D1F01300; Tue, 27 Oct 2026 15:46:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793116019; bh=seQJ0RkpYsv0DnDnr/texKmVDxEFVMoOUeLo6OCf//M=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=UhCwhlHWqRSNVp4V+PNk+6LOLtxBDSg4RhoIkr0OuVQoKO77yc1WMcPQ/qci8QG1+ n55kHT7Ssw87wyF8y4YnNchXx2zle0vmSX41KWVTtuqkzl/SzeFaF1U/RPrmXspkKt hk/DDiICVG1ziAdCCYKnrz6UAgUeqtZAd0w30XWfQxYTXTeXxFWEedK537/wSL7AMl 19zZr/IgEn3PEzEgbbbgJqtFp+LA7Px2HDTnkazCYYWye2Qnm94zoo2gbmDK+451sS WqdWnzHPIKR9biYySf+1pl5K+iB+NW/6RXNmoSOLmWQB4Ow7P9HDBSdVBsyLRGb1b7 1JeOZ/VEVaViw== From: "Vlastimil Babka (SUSE)" Date: Tue, 27 Oct 2026 16:46:33 +0100 Subject: [PATCH 7/9] mm: page_isolation: do not take slab pages for free X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261027-pgalloc-ai-hotfixes-v1-7-9c7d1aca801e@kernel.org> References: <20261027-pgalloc-ai-hotfixes-v1-0-9c7d1aca801e@kernel.org> In-Reply-To: <20261027-pgalloc-ai-hotfixes-v1-0-9c7d1aca801e@kernel.org> To: Andrew Morton , Zi Yan , Shakeel Butt , Mike Rapoport , David Hildenbrand , Oscar Salvador , "Matthew Wilcox (Oracle)" Cc: Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Vlastimil Babka (SUSE)" , Josef Bacik X-Mailer: b4 0.16.0 X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 55110180003 X-Spam-Status: No, score=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-Stat-Signature: pgiz9xy6dxjkazo36mpb5yaqc7t1oepr X-HE-Tag: 1793116020-681131 X-HE-Meta: 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 J1I9IDLN NKTrp7VF2n6qfwUc9zku6bGQweDQboNV63y4uSr9U4HDvjNkYXyq/3ZSZncGL1JRF+CaYfxNnJSmG9yqsPf1B4Xgz1hiriOj2TONhSOSNQjvnFJFJe6+3HlmNb9DCXuM9D72lKivSjzTngwC3/ySM3K4Di4lzSt2VmTJURwurYVzCXKwNKEA3rPZM1MosHWUcWTdRsgCyBecepotB57GXoAoXxYRI1eporXkJaV3VELKTi+dZs5zCea9Ra7fpHwkEaayW2rv17J7Hnhzh61zBqBVrDy2D2rWqea3/mLNhOTQqzXdx1p15jAb2CpeTAn0JVLXFJ+KxhWQ5iqUpExPqBa9/W8OLsy//lysc Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 From: Josef Bacik page_is_unmovable() regards a page with a reference count of zero as free or about to be freed. Since slab allocates frozen pages, they will be wrongly considered to be freed if order 0 (higher-order compound pages are caught earlier). If such slabs are the only unmovable pages of a memory block, memory offlining now isolates the block, this can lead to offline_pages() looping without progress. Thus detect the slab pages as removable to return -EBUSY, as would happen before commit 9aec2fb0fd5e ("slab: allocate frozen pages"). Fixes: 9aec2fb0fd5e ("slab: allocate frozen pages") Assisted-by: LLM Signed-off-by: Josef Bacik Signed-off-by: David Hildenbrand (Arm) Signed-off-by: Vlastimil Babka (SUSE) --- mm/memory_hotplug.c | 7 +++++++ mm/page_isolation.c | 7 +++++++ 2 files changed, 14 insertions(+) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 796af1028ee2..e773a7d54165 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1847,6 +1847,13 @@ static int scan_movable_pages(unsigned long start, unsigned long end, if (PageOffline(page) && page_count(page)) return -EBUSY; + /* + * A page that was allocated, but was not a slab page yet, when + * its pageblock was isolated. + */ + if (PageSlab(page)) + return -EBUSY; + folio = page_folio(page); if (!folio_test_hugetlb(folio)) continue; diff --git a/mm/page_isolation.c b/mm/page_isolation.c index 5aaad037384e..f4f0571607ab 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -74,6 +74,13 @@ bool page_is_unmovable(struct zone *zone, struct page *page, return false; } + /* + * Slab pages are frozen: do not take their reference count of zero + * for that of a free page. + */ + if (PageSlab(page)) + return true; + /* * We can't use page_count without pin a page * because another CPU can free compound page. -- 2.56.0