From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E1BEE566C5C; Wed, 9 Sep 2026 13:34:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788960854; cv=none; b=PDxhLdSP9pqkeqE/+cT5ej8VB7/nykrTQxXIXQQKNyaZqnYhmLfaOkWHVuGvZ+xK4SlC+wlwHgMgT/EkSQXal7Q37QhrAXv9z9Z1kBejDN9wNnXH+D29Dmc5izAcDRhCRcbTqTmSowDcRjPkEs/9o3W6XcUvzjHHccpNmeNO0Zg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788960854; c=relaxed/simple; bh=vj5TwCzhlLxvUe7A+Bx3R9PGajolUon6lM6RJzWmxHU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=YLZOWFqeG1xa3swSyD0db8My0AI62kWsFxsSaSJpJGL04GRtYR1CK+UY01LyyGx9pWLyCFvJL4qSR1un54TXODYOT5JOiUHGnBRXUaa8CvlcmpZvQNSGsSLU5z0Ymq4FzCWqIVYdZJx0FRj8FvL+dAC3vxCLHS24K8X4wPnQwEk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VKETAwhb; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VKETAwhb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D97AA1F00A3A; Wed, 9 Sep 2026 13:34:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788960852; bh=Vwf3XHFmLke+N9soz5HJtjy5W6jvA8C1cmDilLBFR0E=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=VKETAwhbvv+EK0Gm31QFMYaYfrQJ2PkX9WiTurdg0GqN2atlcsKeEnI2LT69seS1g ckmzVzkRoynOrvTlgBNzG1vsWAhQRsMuS1a7vuZYSDXafGxdgK9TNpx4ebCVmVAjM1 xDU1YFvqp0/x0rO09WvuApW6ngX9ZKM5Vkq7BQ8v35OA/CBlRB5ViylH9nulLN/f29 5dnXJYPV5oRwG4/vm/WSmAWMIcDVIe38hgrg+TvfeE1NJrKE8c5xy9uZKJTJnaRbyS OkQib97F1RX0R0/WJwLRKYGE5XY9OxKPJH/UsYWzVYILEjG7UPdcd15Pipp0iFaPrd GcwqJZUYV2Rxw== From: "David Hildenbrand (Arm)" Date: Wed, 09 Sep 2026 15:32:55 +0200 Subject: [PATCH 02/12] mm/sparse: refactor sparse_sections_init() Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260909-b4-sparsemem_cleanups-v1-2-008fc8d579fe@kernel.org> References: <20260909-b4-sparsemem_cleanups-v1-0-008fc8d579fe@kernel.org> In-Reply-To: <20260909-b4-sparsemem_cleanups-v1-0-008fc8d579fe@kernel.org> To: Andrew Morton , Lorenzo Stoakes , "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 Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-cxl@vger.kernel.org, driver-core@lists.linux.dev, linux-fsdevel@vger.kernel.org, "David Hildenbrand (Arm)" X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2859; i=david@kernel.org; h=from:subject:message-id; bh=vj5TwCzhlLxvUe7A+Bx3R9PGajolUon6lM6RJzWmxHU=; b=owGbwMvMwCF2/OVpCdfQ3ZWMp9WSGLIWJmg1TG/wTlyzoPKR2TK/dRFzncSdjcw5bZd5zM1// dqqsVqxo5SFQYyDQVZMkSUo+L7By5fraqvd+Jhh5rAygQxh4OIUgInwTWD4ny5++k5Jx/wO5uki oZopr+4wct0S4XQ8sunwR2f+wENn5RgZrr9oaQteGlzRdT11x6xTOw1nq7yNDpm/IaqT039Ki3U fNwA= X-Developer-Key: i=david@kernel.org; a=openpgp; fpr=1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A 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) --- 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); ms->section_mem_map = sparse_encode_early_nid(nid) | SECTION_IS_ONLINE; __section_mark_present(ms, section_nr); @@ -202,18 +207,6 @@ static void __init memory_present(int nid, unsigned long start, unsigned long en } } -/* Initialize memory section metadata for all system memory. */ -void __init sparse_sections_init(void) -{ - unsigned long start, end; - int i, nid; - - sparse_extreme_init(); - - for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) - memory_present(nid, start, end); -} - #ifndef CONFIG_SPARSEMEM_VMEMMAP struct page __init *__populate_section_memmap(unsigned long pfn, unsigned long nr_pages, int nid, struct vmem_altmap *altmap, -- 2.43.0