revert "mm: fix-up zone present pages"

Revert commit 7f1290f2f2a4 ("mm: fix-up zone present pages")

That patch tried to fix a issue when calculating zone->present_pages,
but it caused a regression on 32bit systems with HIGHMEM.  With that
change, reset_zone_present_pages() resets all zone->present_pages to
zero, and fixup_zone_present_pages() is called to recalculate
zone->present_pages when the boot allocator frees core memory pages into
buddy allocator.  Because highmem pages are not freed by bootmem
allocator, all highmem zones' present_pages becomes zero.

Various options for improving the situation are being discussed but for
now, let's return to the 3.6 code.

Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: Chris Clayton <chris2553@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index acd5b68e887128e90f8e59530d77dc3985bf1e97..082e383c1b6f22dc8370fdac789489acbb04ffba 100644 (file)
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -637,7 +637,6 @@ mem_init (void)
 
        high_memory = __va(max_low_pfn * PAGE_SIZE);
 
-       reset_zone_present_pages();
        for_each_online_pgdat(pgdat)
                if (pgdat->bdata->node_bootmem_map)
                        totalram_pages += free_all_bootmem_node(pgdat);

diff --git a/include/linux/mm.h b/include/linux/mm.h
index fa068040273893c27d71461e459e2eb268739396..bcaab4e6fe913ac6e3f2ef0a6c83ea24d8972867 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1684,9 +1684,5 @@ static inline unsigned int debug_guardpage_minorder(void) { return 0; }
 static inline bool page_is_guard(struct page *page) { return false; }
 #endif /* CONFIG_DEBUG_PAGEALLOC */
 
-extern void reset_zone_present_pages(void);
-extern void fixup_zone_present_pages(int nid, unsigned long start_pfn,
-                               unsigned long end_pfn);
-
 #endif /* __KERNEL__ */
 #endif /* _LINUX_MM_H */

diff --git a/mm/bootmem.c b/mm/bootmem.c
index 434be4ae7a0495817267e5e100c68f47c2006415..f468185b3b28a517aaceb79b80e7f799df0dfc6f 100644 (file)
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -198,8 +198,6 @@ static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
                        int order = ilog2(BITS_PER_LONG);
 
                        __free_pages_bootmem(pfn_to_page(start), order);
-                       fixup_zone_present_pages(page_to_nid(pfn_to_page(start)),
-                                       start, start + BITS_PER_LONG);
                        count += BITS_PER_LONG;
                        start += BITS_PER_LONG;
                } else {
@@ -210,9 +208,6 @@ static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
                                if (vec & 1) {
                                        page = pfn_to_page(start + off);
                                        __free_pages_bootmem(page, 0);
-                                       fixup_zone_present_pages(
-                                               page_to_nid(page),
-                                               start + off, start + off + 1);
                                        count++;
                                }
                                vec >>= 1;
@@ -226,11 +221,8 @@ static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
        pages = bdata->node_low_pfn - bdata->node_min_pfn;
        pages = bootmem_bootmap_pages(pages);
        count += pages;
-       while (pages--) {
-               fixup_zone_present_pages(page_to_nid(page),
-                               page_to_pfn(page), page_to_pfn(page) + 1);
+       while (pages--)
                __free_pages_bootmem(page++, 0);
-       }
 
        bdebug("nid=%td released=%lx\n", bdata - bootmem_node_data, count);
 

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 56b758ae57d2eeb2230bbcaf3f8e8d4538a15a9d..e4eeacae2b91199142776390bdaef73241416b47 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -106,7 +106,6 @@ static void get_page_bootmem(unsigned long info,  struct page *page,
 void __ref put_page_bootmem(struct page *page)
 {
        unsigned long type;
-       struct zone *zone;
 
        type = (unsigned long) page->lru.next;
        BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
@@ -117,12 +116,6 @@ void __ref put_page_bootmem(struct page *page)
                set_page_private(page, 0);
                INIT_LIST_HEAD(&page->lru);
                __free_pages_bootmem(page, 0);
-
-               zone = page_zone(page);
-               zone_span_writelock(zone);
-               zone->present_pages++;
-               zone_span_writeunlock(zone);
-               totalram_pages++;
        }
 
 }

diff --git a/mm/nobootmem.c b/mm/nobootmem.c
index 714d5d6504708c83c64365618749a84b1da4cd66..bd82f6b314114dc937bea707a70072b299860a08 100644 (file)
--- a/mm/nobootmem.c
+++ b/mm/nobootmem.c
@@ -116,8 +116,6 @@ static unsigned long __init __free_memory_core(phys_addr_t start,
                return 0;
 
        __free_pages_memory(start_pfn, end_pfn);
-       fixup_zone_present_pages(pfn_to_nid(start >> PAGE_SHIFT),
-                       start_pfn, end_pfn);
 
        return end_pfn - start_pfn;
 }
@@ -128,7 +126,6 @@ unsigned long __init free_low_memory_core_early(int nodeid)
        phys_addr_t start, end, size;
        u64 i;
 
-       reset_zone_present_pages();
        for_each_free_mem_range(i, MAX_NUMNODES, &start, &end, NULL)
                count += __free_memory_core(start, end);
 

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c91598b1b4c0adb24e5268c23d19db8fbe9e21cf..7bb35ac0964aaa425b3888e0963e3d7fa2ac1e53 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6098,37 +6098,3 @@ void dump_page(struct page *page)
        dump_page_flags(page->flags);
        mem_cgroup_print_bad_page(page);
 }
-
-/* reset zone->present_pages */
-void reset_zone_present_pages(void)
-{
-       struct zone *z;
-       int i, nid;
-
-       for_each_node_state(nid, N_HIGH_MEMORY) {
-               for (i = 0; i < MAX_NR_ZONES; i++) {
-                       z = NODE_DATA(nid)->node_zones + i;
-                       z->present_pages = 0;
-               }
-       }
-}
-
-/* calculate zone's present pages in buddy system */
-void fixup_zone_present_pages(int nid, unsigned long start_pfn,
-                               unsigned long end_pfn)
-{
-       struct zone *z;
-       unsigned long zone_start_pfn, zone_end_pfn;
-       int i;
-
-       for (i = 0; i < MAX_NR_ZONES; i++) {
-               z = NODE_DATA(nid)->node_zones + i;
-               zone_start_pfn = z->zone_start_pfn;
-               zone_end_pfn = zone_start_pfn + z->spanned_pages;
-
-               /* if the two regions intersect */
-               if (!(zone_start_pfn >= end_pfn || zone_end_pfn <= start_pfn))
-                       z->present_pages += min(end_pfn, zone_end_pfn) -
-                                           max(start_pfn, zone_start_pfn);
-       }
-}