Commit 5576646f authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds

revert "mm: fix-up zone present pages"

Revert commit 7f1290f2 ("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: 's avatarDavid Rientjes <rientjes@google.com>
Tested-by: 's avatarChris Clayton <chris2553@googlemail.com>
Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0f3c42f5
......@@ -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);
......
......@@ -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 */
......@@ -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);
......
......@@ -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++;
}
}
......
......@@ -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);
......
......@@ -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);
}
}
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