Changelog:
v1 -> v2:
* show number of HighTotal before hotremove
* remove CONFIG_HIGHMEM
* cc stable kernels
* add Michal reviewed-by
v2 -> v3:
* correct way to request changes for stable
Logic memory-remove code fails to correctly account the Total High Memory
when a memory block which contains High Memory is offlined as shown in the
example below. The following patch fixes it.
Before logic memory remove:
MemTotal: 7603740 kB
MemFree: 6329612 kB
Buffers: 94352 kB
Cached: 872008 kB
SwapCached: 0 kB
Active: 626932 kB
Inactive: 519216 kB
Active(anon): 180776 kB
Inactive(anon): 222944 kB
Active(file): 446156 kB
Inactive(file): 296272 kB
Unevictable: 0 kB
Mlocked: 0 kB
HighTotal: 7294672 kB
HighFree: 5704696 kB
LowTotal: 309068 kB
LowFree: 624916 kB
After logic memory remove:
MemTotal: 7079452 kB
MemFree: 5805976 kB
Buffers: 94372 kB
Cached: 872000 kB
SwapCached: 0 kB
Active: 626936 kB
Inactive: 519236 kB
Active(anon): 180780 kB
Inactive(anon): 222944 kB
Active(file): 446156 kB
Inactive(file): 296292 kB
Unevictable: 0 kB
Mlocked: 0 kB
HighTotal: 7294672 kB
HighFree: 5181024 kB
LowTotal: 4294752076 kB
LowFree: 624952 kB
Cc: <[email protected]> # 2.6.24
Reviewed-by: Michal Hocko <[email protected]>
Signed-off-by: Wanpeng Li <[email protected]>
---
mm/page_alloc.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 98cbdf6..23b921f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6140,6 +6140,8 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
list_del(&page->lru);
rmv_page_order(page);
zone->free_area[order].nr_free--;
+ if (PageHighMem(page))
+ totalhigh_pages -= 1 << order;
for (i = 0; i < (1 << order); i++)
SetPageReserved((page+i));
pfn += (1 << order);
--
1.8.1.2