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 0A676D3E793 for ; Thu, 11 Dec 2025 05:16:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 415746B0005; Thu, 11 Dec 2025 00:16:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 39ECA6B0007; Thu, 11 Dec 2025 00:16:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 267C66B0008; Thu, 11 Dec 2025 00:16:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 10E346B0005 for ; Thu, 11 Dec 2025 00:16:15 -0500 (EST) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 56FB25B205 for ; Thu, 11 Dec 2025 05:16:14 +0000 (UTC) X-FDA: 84206029068.03.91030C5 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) by imf13.hostedemail.com (Postfix) with ESMTP id 18F8320004 for ; Thu, 11 Dec 2025 05:16:11 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=EsqaK+b4; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=QIElUVwL; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=nBItFmQX; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=iTBATg1k; spf=pass (imf13.hostedemail.com: domain of osalvador@suse.de designates 195.135.223.131 as permitted sender) smtp.mailfrom=osalvador@suse.de; dmarc=pass (policy=none) header.from=suse.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1765430172; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ers3ixHL8W9DPh68jGWp3T9AioXIVuTQmqnETwRdD1Q=; b=4jCF5ANoACzlo4FY09NOIATIgYPGVu3GtkhrK7NZO9WV/pxUkxpbHQgnUkhEwun4i7ULvE 6ji9GtVm0EFmeEt4t47/p3Tlk779RWlQbMLBahPx8BwJHHkdOQ8NtQD5dWCwDkVRp3xY9G ydfJHx1VprDSHUX7cpHehn0E87houhY= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1765430172; a=rsa-sha256; cv=none; b=6RdKylRca/Z9EsKEic+VHOFAAdshEw3kiwxNtbc7UIj2bSmc9GP6zD8NyBIq+lnx6OUWMY aeTbBn1J4QcCWAuBsoPjN7zIeZN9E6rMtbnnVZ/NLnJZM4F0sShd9oYlNNf7iQjyMHyH5y TnSxaBDxWhuBb27246428zahHilrUCk= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=EsqaK+b4; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=QIElUVwL; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=nBItFmQX; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=iTBATg1k; spf=pass (imf13.hostedemail.com: domain of osalvador@suse.de designates 195.135.223.131 as permitted sender) smtp.mailfrom=osalvador@suse.de; dmarc=pass (policy=none) header.from=suse.de Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 4CDA05BD5B; Thu, 11 Dec 2025 05:16:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1765430170; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ers3ixHL8W9DPh68jGWp3T9AioXIVuTQmqnETwRdD1Q=; b=EsqaK+b4SdN62gbYftoi+D5PvvwkH079hPM+fkU5bw5Ax5L5rkwToEdoinKV8FxG9K7JiK oNKIK9C+/PR8QQBR4C27BwRMn/e5MzQO5bPySd3rG8DG+vdCTUtjeeg3r46tIcKcSfuBlD dCfhLq+FATW8YrCORtl1cafg874O2TU= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1765430170; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ers3ixHL8W9DPh68jGWp3T9AioXIVuTQmqnETwRdD1Q=; b=QIElUVwLqPS1gNkSQiVhWG76WLcdRnpWy3oGp3AHPxc5pZbbS9LdtPUdi8dtKbrCgJ6wG2 4V6duAIDR3dzgWCA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1765430169; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ers3ixHL8W9DPh68jGWp3T9AioXIVuTQmqnETwRdD1Q=; b=nBItFmQXDkG8I231s6XiKi6WFRS5w/IGziORPA8VO3x8CHa22zWEJuGPwhqrKeEXTV3OZ7 9O3OHJOlNVuJag0avAEd5MckEM/jT2cZgf+WSco09nGnEjchh1PsSuwGewKkg7q2tJIcB9 f3YexrjqfiL1jvZZd/0iZGqiE739/ns= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1765430169; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ers3ixHL8W9DPh68jGWp3T9AioXIVuTQmqnETwRdD1Q=; b=iTBATg1kQPGtuMhJA+/6oDb5O1fjVJ9WaLVN3D3o5QoCZnlSr3pHOgU5NOKAqb1laHW5oR AiSYm09lwYjxF+Cw== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 7789A3EA63; Thu, 11 Dec 2025 05:16:08 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id en1PGphTOmnHHAAAD6G6ig (envelope-from ); Thu, 11 Dec 2025 05:16:08 +0000 Date: Thu, 11 Dec 2025 06:16:02 +0100 From: Oscar Salvador To: Tianyou Li Cc: David Hildenbrand , Mike Rapoport , Wei Yang , linux-mm@kvack.org, Yong Hu , Nanhai Zou , Yuan Liu , Tim Chen , Qiuxu Zhuo , Yu C Chen , Pan Deng , Chen Zhang , linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 2/2] mm/memory hotplug: fix zone->contiguous always false when hotplug Message-ID: References: <20251208152544.1150732-1-tianyou.li@intel.com> <20251208152544.1150732-3-tianyou.li@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251208152544.1150732-3-tianyou.li@intel.com> X-Rspamd-Action: no action X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 18F8320004 X-Stat-Signature: xn55adzphc9rrzpc5ukqwngsmh38ak1a X-Rspam-User: X-HE-Tag: 1765430171-901837 X-HE-Meta: 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 WDTlsMGY AUgbb1EErtckaSnoyYqAR/euKGoLBZMtIaGh9B+bxmWNnXCsLVCVGoMGytB81SuBePeoo20l4ujQL+5fdsVFCe5uQBzSOYZntOYXYvBww0+JTr2Jgkv0RuY0gMildR5oaPNi7W0BA3cVqt6e/ibAu1URy+ESvQ8hjZ16Do7kvPpoisySAjBZIW5XWkXfJNwDOQzppx/5kfsQWgGG6CtRlcF3fa7L+DOUWqhgJQkaFd6n/z3I49C/rGF3AJTP2tGqzanY8NpGqq7dgX/rKUwBUuEkMd1lPaS1r24i8i4g3j947CE13fTdCoEA+G5qgZF6tbkLVWyxOs7A9FBfuaqxqoiUrunW/qsmZ4esAcuTvsRTMaE+U2gyFYyLYl5OAlYWzoI/ZWhZLIMuCUQI= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Dec 08, 2025 at 11:25:44PM +0800, Tianyou Li wrote: > From: Yuan Liu > > Function set_zone_contiguous used __pageblock_pfn_to_page to > check the whole pageblock is in the same zone. One assumption is > the memory section must online, otherwise the __pageblock_pfn_to_page > will return NULL, then the set_zone_contiguous will be false. > When move_pfn_range_to_zone invoked set_zone_contiguous, since the > memory section did not online, the return value will always be false. Then, this means that zone->contiguous was always left false on new memory-hotplug operations, if it was false before? I guess we did not notice this before because it is just an optimization so we always took the long road. Nice catch. > To fix this issue, we removed the set_zone_contiguous from the > move_pfn_range_to_zone, and place it after memory section onlined. > > Function remove_pfn_range_from_zone did not have this issue because > memory section remains online at the time set_zone_contiguous invoked. > > Reviewed-by: Tianyou Li > Reviewed-by: Nanhai Zou > Signed-off-by: Yuan Liu > --- > mm/memory_hotplug.c | 14 ++++++++++---- > 1 file changed, 10 insertions(+), 4 deletions(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index d711f6e2c87f..f548d9180415 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -809,8 +809,7 @@ void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, > { > struct pglist_data *pgdat = zone->zone_pgdat; > int nid = pgdat->node_id; > - const enum zone_contig_state contiguous_state = > - zone_contig_state_after_growing(zone, start_pfn, nr_pages); > + > clear_zone_contiguous(zone); > > if (zone_is_empty(zone)) > @@ -840,8 +839,6 @@ void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, > memmap_init_range(nr_pages, nid, zone_idx(zone), start_pfn, 0, > MEMINIT_HOTPLUG, altmap, migratetype, > isolate_pageblock); > - > - set_zone_contiguous(zone, contiguous_state); > } > > struct auto_movable_stats { > @@ -1150,6 +1147,7 @@ int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages, > { > unsigned long end_pfn = pfn + nr_pages; > int ret, i; > + enum zone_contig_state contiguous_state = ZONE_CONTIG_NO; > > ret = kasan_add_zero_shadow(__va(PFN_PHYS(pfn)), PFN_PHYS(nr_pages)); > if (ret) > @@ -1164,6 +1162,10 @@ int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages, > if (mhp_off_inaccessible) > page_init_poison(pfn_to_page(pfn), sizeof(struct page) * nr_pages); > > + if (IS_ALIGNED(end_pfn, PAGES_PER_SECTION)) > + contiguous_state = zone_contig_state_after_growing(zone, pfn, > + nr_pages); Uhm, I think this deserves a little comment. I guess that if we are not allocating memmap pages worth of a full section, we keep it ZONE_CONTIG_NO. -- Oscar Salvador SUSE Labs