mm: meminit: move page initialization into a separate function

Currently, memmap_init_zone() has all the smarts for initializing a single
page.  A subset of this is required for parallel page initialisation and
so this patch breaks up the monolithic function in preparation.

Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Nathan Zimmer <nzimmer@sgi.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Tested-by: Nate Zimmer <nzimmer@sgi.com>
Tested-by: Waiman Long <waiman.long@hp.com>
Tested-by: Daniel J Blueman <daniel@numascale.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: Scott Norton <scott.norton@hp.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 46 insertions, 33 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 5e6fa06f2784..bc5da2cdfc84 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -764,6 +764,51 @@ static int free_tail_pages_check(struct page *head_page, struct page *page)
         return 0;
 }
 
+static void __meminit __init_single_page(struct page *page, unsigned long pfn,
+                                unsigned long zone, int nid)
+{
+        struct zone *z = &NODE_DATA(nid)->node_zones[zone];
+
+        set_page_links(page, zone, nid, pfn);
+        mminit_verify_page_links(page, zone, nid, pfn);
+        init_page_count(page);
+        page_mapcount_reset(page);
+        page_cpupid_reset_last(page);
+        SetPageReserved(page);
+
+        /*
+         * Mark the block movable so that blocks are reserved for
+         * movable at startup. This will force kernel allocations
+         * to reserve their blocks rather than leaking throughout
+         * the address space during boot when many long-lived
+         * kernel allocations are made. Later some blocks near
+         * the start are marked MIGRATE_RESERVE by
+         * setup_zone_migrate_reserve()
+         *
+         * bitmap is created for zone's valid pfn range. but memmap
+         * can be created for invalid pages (for alignment)
+         * check here not to call set_pageblock_migratetype() against
+         * pfn out of zone.
+         */
+        if ((z->zone_start_pfn <= pfn)
+            && (pfn < zone_end_pfn(z))
+            && !(pfn & (pageblock_nr_pages - 1)))
+                set_pageblock_migratetype(page, MIGRATE_MOVABLE);
+
+        INIT_LIST_HEAD(&page->lru);
+#ifdef WANT_PAGE_VIRTUAL
+        /* The shift won't overflow because ZONE_NORMAL is below 4G. */
+        if (!is_highmem_idx(zone))
+                set_page_address(page, __va(pfn << PAGE_SHIFT));
+#endif
+}
+
+static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone,
+                                        int nid)
+{
+        return __init_single_page(pfn_to_page(pfn), pfn, zone, nid);
+}
+
 static bool free_pages_prepare(struct page *page, unsigned int order)
 {
         bool compound = PageCompound(page);
@@ -4212,7 +4257,6 @@ static void setup_zone_migrate_reserve(struct zone *zone)
 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
                 unsigned long start_pfn, enum memmap_context context)
 {
-        struct page *page;
         unsigned long end_pfn = start_pfn + size;
         unsigned long pfn;
         struct zone *z;
@@ -4233,38 +4277,7 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
                         if (!early_pfn_in_nid(pfn, nid))
                                 continue;
                 }
-                page = pfn_to_page(pfn);
-                set_page_links(page, zone, nid, pfn);
-                mminit_verify_page_links(page, zone, nid, pfn);
-                init_page_count(page);
-                page_mapcount_reset(page);
-                page_cpupid_reset_last(page);
-                SetPageReserved(page);
-                /*
-                 * Mark the block movable so that blocks are reserved for
-                 * movable at startup. This will force kernel allocations
-                 * to reserve their blocks rather than leaking throughout
-                 * the address space during boot when many long-lived
-                 * kernel allocations are made. Later some blocks near
-                 * the start are marked MIGRATE_RESERVE by
-                 * setup_zone_migrate_reserve()
-                 *
-                 * bitmap is created for zone's valid pfn range. but memmap
-                 * can be created for invalid pages (for alignment)
-                 * check here not to call set_pageblock_migratetype() against
-                 * pfn out of zone.
-                 */
-                if ((z->zone_start_pfn <= pfn)
-                    && (pfn < zone_end_pfn(z))
-                    && !(pfn & (pageblock_nr_pages - 1)))
-                        set_pageblock_migratetype(page, MIGRATE_MOVABLE);
-
-                INIT_LIST_HEAD(&page->lru);
-#ifdef WANT_PAGE_VIRTUAL
-                /* The shift won't overflow because ZONE_NORMAL is below 4G. */
-                if (!is_highmem_idx(zone))
-                        set_page_address(page, __va(pfn << PAGE_SHIFT));
-#endif
+                __init_single_pfn(pfn, zone, nid);
         }
 }