From: "David Hildenbrand (Arm)" <david@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
Oscar Salvador <osalvador@suse.de>,
Axel Rasmussen <axelrasmussen@google.com>,
Yuanchu Xie <yuanchu@google.com>, Wei Xu <weixugc@google.com>,
Lorenzo Stoakes <ljs@kernel.org>,
"Liam R. Howlett" <Liam.Howlett@oracle.com>,
Vlastimil Babka <vbabka@kernel.org>,
Mike Rapoport <rppt@kernel.org>,
Suren Baghdasaryan <surenb@google.com>,
Michal Hocko <mhocko@suse.com>,
Sidhartha Kumar <sidhartha.kumar@oracle.com>,
linux-mm@kvack.org, linux-cxl@vger.kernel.org,
linux-riscv@lists.infradead.org,
"David Hildenbrand (Arm)" <david@kernel.org>
Subject: [PATCH v2 11/15] mm: prepare to move subsection_map_init() to mm/sparse-vmemmap.c
Date: Fri, 20 Mar 2026 23:13:43 +0100 [thread overview]
Message-ID: <20260320-sparsemem_cleanups-v2-11-096addc8800d@kernel.org> (raw)
In-Reply-To: <20260320-sparsemem_cleanups-v2-0-096addc8800d@kernel.org>
We want to move subsection_map_init() to mm/sparse-vmemmap.c.
To prepare for getting rid of subsection_map_init() in mm/sparse.c
completely, use a static inline function for !CONFIG_SPARSEMEM_VMEMMAP.
While at it, move the declaration to internal.h and rename it to
"sparse_init_subsection_map()".
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
---
include/linux/mmzone.h | 3 ---
mm/internal.h | 12 ++++++++++++
mm/mm_init.c | 2 +-
mm/sparse.c | 6 +-----
4 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 7bd0134c241c..b694c69dee04 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -2002,8 +2002,6 @@ struct mem_section_usage {
unsigned long pageblock_flags[0];
};
-void subsection_map_init(unsigned long pfn, unsigned long nr_pages);
-
struct page;
struct page_ext;
struct mem_section {
@@ -2396,7 +2394,6 @@ static inline unsigned long next_present_section_nr(unsigned long section_nr)
#define sparse_vmemmap_init_nid_early(_nid) do {} while (0)
#define sparse_vmemmap_init_nid_late(_nid) do {} while (0)
#define pfn_in_present_section pfn_valid
-#define subsection_map_init(_pfn, _nr_pages) do {} while (0)
#endif /* CONFIG_SPARSEMEM */
/*
diff --git a/mm/internal.h b/mm/internal.h
index f98f4746ac41..5f5c45d80aca 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -960,12 +960,24 @@ void memmap_init_range(unsigned long, int, unsigned long, unsigned long,
unsigned long, enum meminit_context, struct vmem_altmap *, int,
bool);
+/*
+ * mm/sparse.c
+ */
#ifdef CONFIG_SPARSEMEM
void sparse_init(void);
#else
static inline void sparse_init(void) {}
#endif /* CONFIG_SPARSEMEM */
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+void sparse_init_subsection_map(unsigned long pfn, unsigned long nr_pages);
+#else
+static inline void sparse_init_subsection_map(unsigned long pfn,
+ unsigned long nr_pages)
+{
+}
+#endif /* CONFIG_SPARSEMEM_VMEMMAP */
+
#if defined CONFIG_COMPACTION || defined CONFIG_CMA
/*
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 969048f9b320..3c5f18537cd1 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -1898,7 +1898,7 @@ static void __init free_area_init(void)
pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
(u64)start_pfn << PAGE_SHIFT,
((u64)end_pfn << PAGE_SHIFT) - 1);
- subsection_map_init(start_pfn, end_pfn - start_pfn);
+ sparse_init_subsection_map(start_pfn, end_pfn - start_pfn);
}
/* Initialise every node */
diff --git a/mm/sparse.c b/mm/sparse.c
index e2048b1fbf5f..c96ac5e70c22 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -185,7 +185,7 @@ static void subsection_mask_set(unsigned long *map, unsigned long pfn,
bitmap_set(map, idx, end - idx + 1);
}
-void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages)
+void __init sparse_init_subsection_map(unsigned long pfn, unsigned long nr_pages)
{
int end_sec_nr = pfn_to_section_nr(pfn + nr_pages - 1);
unsigned long nr, start_sec_nr = pfn_to_section_nr(pfn);
@@ -207,10 +207,6 @@ void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages)
nr_pages -= pfns;
}
}
-#else
-void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages)
-{
-}
#endif
/* Record a memory area against a node. */
--
2.43.0
next prev parent reply other threads:[~2026-03-20 22:14 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-20 22:13 [PATCH v2 00/15] mm: memory hot(un)plug and SPARSEMEM cleanups David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 01/15] mm/memory_hotplug: fix possible race in scan_movable_pages() David Hildenbrand (Arm)
2026-03-23 13:26 ` Lorenzo Stoakes (Oracle)
2026-03-23 13:40 ` David Hildenbrand (Arm)
2026-03-23 14:00 ` Lorenzo Stoakes (Oracle)
2026-03-20 22:13 ` [PATCH v2 02/15] mm/memory_hotplug: remove for_each_valid_pfn() usage David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 03/15] mm/sparse: remove WARN_ONs from (online|offline)_mem_sections() David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 04/15] mm/Kconfig: make CONFIG_MEMORY_HOTPLUG depend on CONFIG_SPARSEMEM_VMEMMAP David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 05/15] mm/memory_hotplug: simplify check_pfn_span() David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 06/15] mm/sparse: remove !CONFIG_SPARSEMEM_VMEMMAP leftovers for CONFIG_MEMORY_HOTPLUG David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 07/15] mm/bootmem_info: remove handling for !CONFIG_SPARSEMEM_VMEMMAP David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 08/15] mm/bootmem_info: avoid using sparse_decode_mem_map() David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 09/15] mm/sparse: remove sparse_decode_mem_map() David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 10/15] mm/sparse: remove CONFIG_MEMORY_HOTPLUG-specific usemap allocation handling David Hildenbrand (Arm)
2026-03-20 22:13 ` David Hildenbrand (Arm) [this message]
2026-03-20 22:13 ` [PATCH v2 12/15] mm/sparse: drop set_section_nid() from sparse_add_section() David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 13/15] mm/sparse: move sparse_init_one_section() to internal.h David Hildenbrand (Arm)
2026-03-23 8:49 ` David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 14/15] mm/sparse: move __section_mark_present() " David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 15/15] mm/sparse: move memory hotplug bits to sparse-vmemmap.c David Hildenbrand (Arm)
2026-03-27 2:58 ` [PATCH v2 00/15] mm: memory hot(un)plug and SPARSEMEM cleanups Andrew Morton
2026-03-27 10:00 ` Lorenzo Stoakes (Oracle)
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