mm: move array mem_section init code out of memory_present()

Patch series "mm/init: minor clean up and improvement".

These are all observed when going through code flow during mm init.

This patch (of 7):

When CONFIG_SPARSEMEM_EXTREME is enabled, mem_section need be initialized
to point at a two-dimensional array, and its 1st dimension of length
NR_SECTION_ROOTS will be dynamically allocated.  Once the allocation is
done, it's available for all nodes.

So take the 1st dimension of mem_section initialization out of
memory_present()(), and put it into memblocks_present() which is a more
appripriate place.

Link: https://lkml.kernel.org/r/20240326061134.1055295-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20240326061134.1055295-2-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: "Mike Rapoport (IBM)" <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/sparse.c b/mm/sparse.c
index aed0951b87fa04d8efabb85cff28cca5aaa9976a..46e88549d1a6a9b62d67755e5c61bd288d27fa80 100644 (file)
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -226,19 +226,6 @@ static void __init memory_present(int nid, unsigned long start, unsigned long en
 {
        unsigned long pfn;
 
-#ifdef CONFIG_SPARSEMEM_EXTREME
-       if (unlikely(!mem_section)) {
-               unsigned long size, align;
-
-               size = sizeof(struct mem_section *) * NR_SECTION_ROOTS;
-               align = 1 << (INTERNODE_CACHE_SHIFT);
-               mem_section = memblock_alloc(size, align);
-               if (!mem_section)
-                       panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
-                             __func__, size, align);
-       }
-#endif
-
        start &= PAGE_SECTION_MASK;
        mminit_validate_memmodel_limits(&start, &end);
        for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
@@ -267,6 +254,19 @@ static void __init memblocks_present(void)
        unsigned long start, end;
        int i, nid;
 
+#ifdef CONFIG_SPARSEMEM_EXTREME
+       if (unlikely(!mem_section)) {
+               unsigned long size, align;
+
+               size = sizeof(struct mem_section *) * NR_SECTION_ROOTS;
+               align = 1 << (INTERNODE_CACHE_SHIFT);
+               mem_section = memblock_alloc(size, align);
+               if (!mem_section)
+                       panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+                             __func__, size, align);
+       }
+#endif
+
        for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid)
                memory_present(nid, start, end);
 }