mm: correctly update zone->managed_pages

Enhance adjust_managed_page_count() to adjust totalhigh_pages for
highmem pages.  And change code which directly adjusts totalram_pages to
use adjust_managed_page_count() because it adjusts totalram_pages,
totalhigh_pages and zone->managed_pages altogether in a safe way.

Remove inc_totalhigh_pages() and dec_totalhigh_pages() from xen/balloon
driver bacause adjust_managed_page_count() has already adjusted
totalhigh_pages.

This patch also fixes two bugs:

1) enhances virtio_balloon driver to adjust totalhigh_pages when
   reserve/unreserve pages.
2) enhance memory_hotplug.c to adjust totalhigh_pages when hot-removing
   memory.

We still need to deal with modifications of totalram_pages in file
arch/powerpc/platforms/pseries/cmm.c, but need help from PPC experts.

[akpm@linux-foundation.org: remove ifdef, per Wanpeng Li, virtio_balloon.c cleanup, per Sergei]
[akpm@linux-foundation.org: export adjust_managed_page_count() to modules, for drivers/virtio/virtio_balloon.c]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <sworddragon2@aol.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index bd3ae32..0098810 100644 (file)
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -148,7 +148,7 @@ static void fill_balloon(struct virtio_balloon *vb, size_t num)
                }
                set_page_pfns(vb->pfns + vb->num_pfns, page);
                vb->num_pages += VIRTIO_BALLOON_PAGES_PER_PAGE;
-               totalram_pages--;
+               adjust_managed_page_count(page, -1);
        }
 
        /* Did we get any? */
@@ -163,8 +163,9 @@ static void release_pages_by_pfn(const u32 pfns[], unsigned int num)
 
        /* Find pfns pointing at start of each page, get pages and free them. */
        for (i = 0; i < num; i += VIRTIO_BALLOON_PAGES_PER_PAGE) {
-               balloon_page_free(balloon_pfn_to_page(pfns[i]));
-               totalram_pages++;
+               struct page *page = balloon_pfn_to_page(pfns[i]);
+               balloon_page_free(page);
+               adjust_managed_page_count(page, 1);
        }
 }
 

diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 930fb68..c8aab4e 100644 (file)
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -89,14 +89,6 @@ EXPORT_SYMBOL_GPL(balloon_stats);
 /* We increase/decrease in batches which fit in a page */
 static xen_pfn_t frame_list[PAGE_SIZE / sizeof(unsigned long)];
 
-#ifdef CONFIG_HIGHMEM
-#define inc_totalhigh_pages() (totalhigh_pages++)
-#define dec_totalhigh_pages() (totalhigh_pages--)
-#else
-#define inc_totalhigh_pages() do {} while (0)
-#define dec_totalhigh_pages() do {} while (0)
-#endif
-
 /* List of ballooned pages, threaded through the mem_map array. */
 static LIST_HEAD(ballooned_pages);
 
@@ -132,9 +124,7 @@ static void __balloon_append(struct page *page)
 static void balloon_append(struct page *page)
 {
        __balloon_append(page);
-       if (PageHighMem(page))
-               dec_totalhigh_pages();
-       totalram_pages--;
+       adjust_managed_page_count(page, -1);
 }
 
 /* balloon_retrieve: rescue a page from the balloon, if it is not empty. */
@@ -151,13 +141,12 @@ static struct page *balloon_retrieve(bool prefer_highmem)
                page = list_entry(ballooned_pages.next, struct page, lru);
        list_del(&page->lru);
 
-       if (PageHighMem(page)) {
+       if (PageHighMem(page))
                balloon_stats.balloon_high--;
-               inc_totalhigh_pages();
-       } else
+       else
                balloon_stats.balloon_low--;
 
-       totalram_pages++;
+       adjust_managed_page_count(page, 1);
 
        return page;
 }
@@ -372,9 +361,7 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
 #endif
 
                /* Relinquish the page back to the allocator. */
-               ClearPageReserved(page);
-               init_page_count(page);
-               __free_page(page);
+               __free_reserved_page(page);
        }
 
        balloon_stats.current_pages += rc;

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index fe09515..83aff0a 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1263,7 +1263,7 @@ static void __init gather_bootmem_prealloc(void)
                 * side-effects, like CommitLimit going negative.
                 */
                if (h->order > (MAX_ORDER - 1))
-                       totalram_pages += 1 << h->order;
+                       adjust_managed_page_count(page, 1 << h->order);
        }
 }
 

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 814ecb2..5e34922 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -772,20 +772,13 @@ EXPORT_SYMBOL_GPL(__online_page_set_limits);
 
 void __online_page_increment_counters(struct page *page)
 {
-       totalram_pages++;
-
-#ifdef CONFIG_HIGHMEM
-       if (PageHighMem(page))
-               totalhigh_pages++;
-#endif
+       adjust_managed_page_count(page, 1);
 }
 EXPORT_SYMBOL_GPL(__online_page_increment_counters);
 
 void __online_page_free(struct page *page)
 {
-       ClearPageReserved(page);
-       init_page_count(page);
-       __free_page(page);
+       __free_reserved_page(page);
 }
 EXPORT_SYMBOL_GPL(__online_page_free);
 
@@ -983,7 +976,6 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
                return ret;
        }
 
-       zone->managed_pages += onlined_pages;
        zone->present_pages += onlined_pages;
 
        pgdat_resize_lock(zone->zone_pgdat, &flags);
@@ -1572,15 +1564,13 @@ repeat:
        /* reset pagetype flags and makes migrate type to be MOVABLE */
        undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
        /* removal success */
-       zone->managed_pages -= offlined_pages;
+       adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages);
        zone->present_pages -= offlined_pages;
 
        pgdat_resize_lock(zone->zone_pgdat, &flags);
        zone->zone_pgdat->node_present_pages -= offlined_pages;
        pgdat_resize_unlock(zone->zone_pgdat, &flags);
 
-       totalram_pages -= offlined_pages;
-
        init_per_zone_wmark_min();
 
        if (!populated_zone(zone)) {

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2437a7e..1481439 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -780,11 +780,7 @@ void __init init_cma_reserved_pageblock(struct page *page)
        set_page_refcounted(page);
        set_pageblock_migratetype(page, MIGRATE_CMA);
        __free_pages(page, pageblock_order);
-       totalram_pages += pageblock_nr_pages;
-#ifdef CONFIG_HIGHMEM
-       if (PageHighMem(page))
-               totalhigh_pages += pageblock_nr_pages;
-#endif
+       adjust_managed_page_count(page, pageblock_nr_pages);
 }
 #endif
 
@@ -5207,8 +5203,13 @@ void adjust_managed_page_count(struct page *page, long count)
        spin_lock(&managed_page_count_lock);
        page_zone(page)->managed_pages += count;
        totalram_pages += count;
+#ifdef CONFIG_HIGHMEM
+       if (PageHighMem(page))
+               totalhigh_pages += count;
+#endif
        spin_unlock(&managed_page_count_lock);
 }
+EXPORT_SYMBOL(adjust_managed_page_count);
 
 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
 {