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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 61B83CD4F3D for ; Wed, 20 May 2026 15:31:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A01936B00E3; Wed, 20 May 2026 11:31:28 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9D95E6B00EA; Wed, 20 May 2026 11:31:28 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8C8336B00ED; Wed, 20 May 2026 11:31:28 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 7B0486B00E3 for ; Wed, 20 May 2026 11:31:28 -0400 (EDT) Received: from smtpin06.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 1D5B7C18C1 for ; Wed, 20 May 2026 15:31:28 +0000 (UTC) X-FDA: 84788187456.06.1EF0D53 Received: from out-180.mta1.migadu.com (out-180.mta1.migadu.com [95.215.58.180]) by imf24.hostedemail.com (Postfix) with ESMTP id CD61B18000E for ; Wed, 20 May 2026 15:31:25 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=UrD4QznM; spf=pass (imf24.hostedemail.com: domain of lance.yang@linux.dev designates 95.215.58.180 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1779291086; 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=gxePXEMQDWwNnRA4fuUAEJ8toZ4JkLQ6obW+0ibr2gg=; b=ozSx2UWrK3P2VAxZzL6u3A4AXqV4p1N/88IXor1JOJ/KNf40S9fMitkjU1pL3xaqmFrGi2 azF31MpmllGdNf8DTq1PmUSQJazE3gq23ZZsMrCRXfRuOf1JTjelrhN23wSkic0uVXk0Zt CKLKMdRgM6rPwhQVdKnbyC8gG9oBVkI= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=UrD4QznM; spf=pass (imf24.hostedemail.com: domain of lance.yang@linux.dev designates 95.215.58.180 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1779291086; a=rsa-sha256; cv=none; b=WmREN/4eNJOVwRVp0ZbEedWsFcSjbB38DB9vnmXdNe+vnDWOZwGupHkptjoCK3a6FSBR4y AVP+gi0pmBdbB1qtH+pnyDv9W19JWeA1YYjS2OseNORx8RqRf5NevVzUkG2hp9bFv5uWRO SXGSExe8j+7qD4CSOxIEfhGVD9y++bg= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1779291083; h=from:from: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; bh=gxePXEMQDWwNnRA4fuUAEJ8toZ4JkLQ6obW+0ibr2gg=; b=UrD4QznMUDmQ0luAlbLeSSiws6nZUUkmtwBztn8k6zeWl1F6tpAnuJzA7kqzv5F400/CJu tsnsT0njTgvs2egS7NWnQZ3sFoLN2sNldH6aweT3nAwMm/SUsrALg/hSZ40qnAurfGkQIy 7NDdgJx0NZYt+FVg9eFvyCYbotjwbEw= From: Lance Yang To: david@kernel.org Cc: davem@davemloft.net, andreas@gaisler.com, rppt@kernel.org, akpm@linux-foundation.org, agordeev@linux.ibm.com, gerald.schaefer@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, maddy@linux.ibm.com, mpe@ellerman.id.au, npiggin@gmail.com, chleroy@kernel.org, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, surenb@google.com, mhocko@suse.com, sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Lance Yang Subject: Re: [PATCH 5/8] mm/bootmem_info: stop marking the pgdat as NODE_INFO Date: Wed, 20 May 2026 23:30:55 +0800 Message-Id: <20260520153055.61173-1-lance.yang@linux.dev> In-Reply-To: <20260511-bootmem_info_prep-v1-5-3fb0be6fc688@kernel.org> References: <20260511-bootmem_info_prep-v1-5-3fb0be6fc688@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Queue-Id: CD61B18000E X-Rspamd-Server: rspam06 X-Stat-Signature: msbqbakoy5iie6ubysjox5g58usgnf7p X-HE-Tag: 1779291085-886540 X-HE-Meta: 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 8K0ji/fu G9E2cviNYYYKdAjzo34o+myanx/e6zFAGjNrX1wRsnkinpKpaOy16HYpBi4bW3tz0L8nErO9y+QBYT9eha3G1y4cKND2d6pbRBLCqG1q6USZHBGRc/ddz93QUgnTG9qCf1DsBMb8rK5mRiPQSPuojnzAmqDry5r7nQXelDQUd233wFQhmukcCezVlDlARrQng7UbppYivqIJCPPCpb3BGpy12vzWaRb5XEFfhi7sfwq6A/+wkOEMRWGoPVCO9nwooWh+DfP0HK2shpYtMJgJSHo5htg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, May 11, 2026 at 04:05:33PM +0200, David Hildenbrand (Arm) wrote: >We removed the last user of NODE_INFO in commit 119c31caa59e ("mm/sparse: >remove !CONFIG_SPARSEMEM_VMEMMAP leftovers for CONFIG_MEMORY_HOTPLUG"). > >But it really was never used it besides for safety-checks ever since it was >introduced in commit 04753278769f ("memory hotplug: register section/node >id to free"), where we had the comment: > > 5) The node information like pgdat has similar issues. But, this > will be able to be solved too by this. > (Not implemented yet, but, remembering node id in the pages.) > >Of course, that never happened, and we are not planning on freeing the >node data (pgdat/pglist_data), during memory hotunplug. > >So let's just stop marking the pgdat as NODE_INFO. > >Signed-off-by: David Hildenbrand (Arm) >--- > mm/bootmem_info.c | 9 +-------- > 1 file changed, 1 insertion(+), 8 deletions(-) > >diff --git a/mm/bootmem_info.c b/mm/bootmem_info.c >index 74c1116626c8..cce1d560f094 100644 >--- a/mm/bootmem_info.c >+++ b/mm/bootmem_info.c >@@ -62,15 +62,8 @@ static void __init register_page_bootmem_info_section(unsigned long start_pfn) > > void __init register_page_bootmem_info_node(struct pglist_data *pgdat) > { >- unsigned long i, pfn, end_pfn, nr_pages; >+ unsigned long pfn, end_pfn; > int node = pgdat->node_id; >- struct page *page; >- >- nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT; >- page = virt_to_page(pgdat); >- >- for (i = 0; i < nr_pages; i++, page++) >- get_page_bootmem(node, page, NODE_INFO); Cool. IIUC, pgdat isn't freed during memory hotremove. Offline nodes stick around and can get reinitialized on hotadd, so NODE_INFO doesn't buy us anything here :D LGTM, feel free to add: Reviewed-by: Lance Yang