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 786A5C79FB9 for ; Thu, 10 Sep 2026 14:38:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 929766B008A; Thu, 10 Sep 2026 10:38:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 908F56B0092; Thu, 10 Sep 2026 10:38:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 83E0B6B009B; Thu, 10 Sep 2026 10:38:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 5F68C6B008A for ; Thu, 10 Sep 2026 10:38:16 -0400 (EDT) Received: from smtpin03.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id E52C11C2346 for ; Thu, 10 Sep 2026 14:38:15 +0000 (UTC) X-FDA: 85198107750.03.E46D849 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf05.hostedemail.com (Postfix) with ESMTP id 504B8100003 for ; Thu, 10 Sep 2026 14:38:14 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=I5pFoW74; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf05.hostedemail.com: domain of ljs@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=ljs@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1789051094; 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=MK4zUJB9+wzOo/C/BizaklPC9wZpzdasI2Hvs/7YAKY=; b=2cGaEDeWq3l0ALzWz91rdhvpBWDcCVJxVvkM7x3FC1N81hnVDtlGPDKnEladU1rPhhaUAN TgvQfWUb9XvBgHgWu1epi5gKuq4nKyFdIAMbNWQL66ViR03+EGn1iVHJWstFVRCtn6CX/f +yld2MPkc7/fr22o3R7hxUmXCdSeeSQ= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1789051094; b=5ejS1WF53USWs41yC77RDNOW4jGWoWFVzc/YI71y6aw0IEZ35ZhY5QSCfGsrtoKNbqHAl0 PK02ENpxE0gZb4FDXkEN+J+iDeogAJ8AGP/VW98rybKVgDb5bd2JXszSlJIOJIqbFJWn28 8gBTSaIQUIo00nFBb/ivYSdf3qyoDiQ= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=I5pFoW74; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf05.hostedemail.com: domain of ljs@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=ljs@kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id AF8B660202; Thu, 10 Sep 2026 14:38:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5071B1F000FF; Thu, 10 Sep 2026 14:38:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789051093; bh=MK4zUJB9+wzOo/C/BizaklPC9wZpzdasI2Hvs/7YAKY=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=I5pFoW746SSPNXz9o8Gr2kFBOSCOW/xePk4xTDfyqFgvoAmf0tODgEET0eRkncke9 XZfiCBHYBPe3zMjtgMElX9WcKhEFwpWObpy1cDNNXfZ82Q10+JbzOCJjnJSyAnK53x 7vuGYjH/35JsI1+OK1y/muHGz9/onzcxiv9oEU+nc6hi8+rY0ajtvZgR1zgS1lrdUl MYlX5KHgZuMvcheoJuo7cNLrgBsMOqearr46U9pUJlt6Hu0phy1p2dpwJ5CUSI15fd AtCXxUto9Jhl3wqLtR0RwSlAn2asx1Z4EZT3Es7V9UREdrzYdWck5ixnGT2gsty54b uZsXfs+QijvtQ== Date: Thu, 10 Sep 2026 15:38:03 +0100 From: "Lorenzo Stoakes (ARM)" To: "David Hildenbrand (Arm)" Cc: Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kairui Song , Qi Zheng , Shakeel Butt , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , Brendan Jackman , Johannes Weiner , Zi Yan , Oscar Salvador , Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , Jan Kiszka , Kieran Bingham , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-cxl@vger.kernel.org, driver-core@lists.linux.dev, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 02/12] mm/sparse: refactor sparse_sections_init() Message-ID: References: <20260909-b4-sparsemem_cleanups-v1-0-008fc8d579fe@kernel.org> <20260909-b4-sparsemem_cleanups-v1-2-008fc8d579fe@kernel.org> <44f7ce5c-b75c-4c44-9202-1d2d3a1de965@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <44f7ce5c-b75c-4c44-9202-1d2d3a1de965@kernel.org> X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 504B8100003 X-Stat-Signature: m75ide8p7aytsqxk7oxrbfd5miyccn3w X-HE-Tag: 1789051094-849172 X-HE-Meta: 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 c8dsQywd TUpbL+LfJDMQsmVITtb9wTSu59cNeHJgZvOLdtqUWb8tjoQ/McXCIMz7x+q7y5KGWko7EKr1ZiZtsPWddPvrK3r/wX58t4PlwW/72JMBL0SlcuDOWKC1K1TM3ux0QdEF/vJaalcrIAfOCpE+UoeZ4uJdSOj7ckblouhcgLY/Vg10R3XkdneZFurMHb9aU/nZg/Pi869Jany+Zxhs1EfMxysa15wEoL3c3cW/wLOCshG9X24cUeTi9MspyitfnidVv/d8zqyMWlLzV9Qn8Jp0FycafNOvhrHOFohfk4D3pZG3f+xdQIJYAwf4qeXPvQBupBAJJUgCPRDL2uJ5jP6K3YnKM+31Qi5/HKyMaNQJFWBcSl50= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Sep 10, 2026 at 04:30:43PM +0200, David Hildenbrand (Arm) wrote: > On 9/10/26 15:29, Lorenzo Stoakes (ARM) wrote: > > On Wed, Sep 09, 2026 at 03:32:55PM +0200, David Hildenbrand (Arm) wrote: > >> memory_present() really identifies+prepares all early sections so the > >> initialization in sparse_init() can properly iterating them to > >> initialize metadata. > >> > >> Let's just inline memory_present() into sparse_sections_init() and > >> cleaning up the code a bit while at it: make it clear that we are operating > >> on pfns. > >> > >> Note that we call set_section_nid() now only if the section > >> was not already created earlier. Now, there is no more inconsistency > >> between what we (temporarily) store in ms->section_mem_map and what > >> we store in our section->nid array. > >> > >> Signed-off-by: David Hildenbrand (Arm) > > > > In general please keep move/refactor steps separate. It makes it harder to > > review when two things are going on at one time. > > > > But I guess in this case the diff wouldn't be that different. > > Yeah, I actually want back and forth here and decided to keep it simple. Yeah, this one's a bit of a blurry line but I think fine as it is! > > > > > Anyway seems reasonable so: > > > > Acked-by: Lorenzo Stoakes (ARM) > > Thanks! > > > > >> --- > >> mm/sparse.c | 41 +++++++++++++++++------------------------ > >> 1 file changed, 17 insertions(+), 24 deletions(-) > >> > >> diff --git a/mm/sparse.c b/mm/sparse.c > >> index 6a6d258862904..36e3d854febc5 100644 > >> --- a/mm/sparse.c > >> +++ b/mm/sparse.c > >> @@ -179,22 +179,27 @@ static inline unsigned long first_present_section_nr(void) > >> return next_present_section_nr(-1); > >> } > >> > >> -/* Record a memory area against a node. */ > >> -static void __init memory_present(int nid, unsigned long start, unsigned long end) > >> +void __init sparse_sections_init(void) > >> { > >> - unsigned long pfn; > >> + unsigned long pfn, start_pfn, end_pfn; > >> + int i, nid; > >> + > >> + sparse_extreme_init(); > >> > >> - start &= PAGE_SECTION_MASK; > >> - mminit_validate_memmodel_limits(&start, &end); > >> - for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) { > >> - unsigned long section_nr = pfn_to_section_nr(pfn); > >> - struct mem_section *ms; > >> + for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) { > >> + start_pfn &= PAGE_SECTION_MASK; > >> + mminit_validate_memmodel_limits(&start_pfn, &end_pfn); > >> > >> - sparse_index_init(section_nr, nid); > >> - set_section_nid(section_nr, nid); > >> + for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { > >> + unsigned long section_nr = pfn_to_section_nr(pfn); > >> + struct mem_section *ms; > >> > >> - ms = __nr_to_section(section_nr); > >> - if (!ms->section_mem_map) { > >> + sparse_index_init(section_nr, nid); > >> + ms = __nr_to_section(section_nr); > >> + if (ms->section_mem_map) > >> + continue; > >> + > >> + set_section_nid(section_nr, nid); > > > > So the main change seems to be calling set_section_nid() only if > > !ms->section_mem_map (and obv. calculating ms earlier), as described in the > > commit msg. > > Yes! I also played with having that in a standalone patch but judged that it's > not really worth it. I can move it to a separate patch if you think it would be > better! No need, not really a big diff delta and you call it out in the commit msg! > > -- > Cheers, > > David -- Cheers, Lorenzo