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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 51606CD5BC8 for ; Tue, 26 May 2026 12:31:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=CMSIxvChsdu1V/cdy6UaokWB5ztGbjE2wCafo6jTDRU=; b=CrXPm8zFG6SP9XUfouGAQF7RDD wJx21NqwBgTlRRYFNOjkeUoeLWeyQCOtx0MncgjccTFRFID6akjAbc7G90VtEIjddgnutC2uN+diu VRMXnDKWENHmnf4+32/eS7azzzUypcmbaK2yF4S5N6Y1e6WT5HjWv2rYXG8YpCXDdRaOFpNP4wlG2 8jdbGD4FTD6QNA9v7yJ8k0tnVaupx6ZcdbrooAWwpJ46T3w9Zfj1HV+7ds+uf9me8BdIpVwcsW7p9 LTkWu8VZqU6fB5qWN8RJy8+m4AJ07t1QkGGe2OygZwe1wQYmdB8CLBThJ8bDpsKcin/o50KC7XGKB URjApiew==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wRqw9-00000001v2c-3akM; Tue, 26 May 2026 12:31:09 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wRqw7-00000001v21-0O55 for linux-arm-kernel@lists.infradead.org; Tue, 26 May 2026 12:31:08 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 6279E43D03; Tue, 26 May 2026 12:31:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 43AAA1F000E9; Tue, 26 May 2026 12:31:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779798666; bh=CMSIxvChsdu1V/cdy6UaokWB5ztGbjE2wCafo6jTDRU=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=FN9HaspCvpo45qFUkCrH02hplPk1gBW2uGeTih14XCaOD8sfCm/g869W4yziDNgt3 YKudIUanXvtWU68PiPCDbtCPimZtF1DnjV06TYb0gnjB285yALRZoOGAxV1awxMUxm BfFkFYSLOacWK5oLz8FoT72P6eBS3q2QYdBwhQPZZLXvt1b1edkO/3Fw8KDYeIh/DG IooDTEi8jvk4wioMvL+w8hB0ahsCVoDFZ1ZRZe/Y6uvWR7168SzrtbK2m5Ju1sQsn5 zW4Sy/JmAyiUVXhn/vnX19K/fWrUWfEUrUb7Iy2kn+XlJ6nA6P4WkRJY45064oKHj9 WukAgd3mtnxaA== Message-ID: <1be38262-53de-4a27-9841-393e12fc1475@kernel.org> Date: Tue, 26 May 2026 14:31:01 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] arm64: mm: call pagetable dtor when freeing hot-removed page tables To: Kevin Brodsky , Vishal Moola , Catalin Marinas Cc: Andrew Morton , Alistair Popple , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, will@kernel.org References: <20260521032730.2104017-1-apopple@nvidia.com> <20260521153130.d7d5cd060f7522f894252333@linux-foundation.org> <92450154-e1ab-46e4-b23d-eaa59c9cdd3b@arm.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260526_053107_178474_75C50661 X-CRM114-Status: GOOD ( 12.02 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 5/26/26 13:54, Kevin Brodsky wrote: > On 22/05/2026 11:36, Vishal Moola wrote: >>> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c >>> index 4c8959153ac4..9d42cbddce27 100644 >>> --- a/arch/arm64/mm/mmu.c >>> +++ b/arch/arm64/mm/mmu.c >>> @@ -1441,6 +1441,9 @@ static void free_hotplug_page_range(struct page *page, size_t size, >>> >>> static void free_hotplug_pgtable_page(struct page *page) >>> { >>> + if (folio_test_pgtable(page_folio(page))) >> This should work. >> >>> + pagetable_dtor(page_ptdesc(page)); >>> + >>> free_hotplug_page_range(page, PAGE_SIZE, NULL); >> In the case we presumably have a page table page (ptdesc) at this >> point, we should really be freeing it with pagetable_free() as well. > > Agreed, I think this is the right thing to do, something like: > > if (folio_test_pgtable(page_folio(page))) > pagetable_dtor_free(page_ptdesc(page)); else > free_hotplug_page_range(page, PAGE_SIZE, NULL); That code pattern is wrong. folio_test_pgtable() shouldn't exist. In the future, something is either a pgtable or a folio, not both. So check the type against the page, not the folio. -- Cheers, David