| From | Luis Henriques <> | Subject | [PATCH 37/98] mm/memory-hotplug: fix lowmem count overflow when offline pages | Date | Thu, 11 Jul 2013 15:24:07 +0100 |
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3.5.7.17 -stable review patch. If anyone has any objections, please let me know.
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From: Wanpeng Li <liwanp@linux.vnet.ibm.com>
commit cea27eb2a202959783f81254c48c250ddd80e129 upstream.
The logic for the 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
[mhocko@suse.cz: fix CONFIG_HIGHMEM=n build] Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [ luis: backported to 3.5: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- mm/page_alloc.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 0ed96c7..63e6fa4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5911,6 +5911,10 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) zone->free_area[order].nr_free--; __mod_zone_page_state(zone, NR_FREE_PAGES, - (1UL << order)); +#ifdef CONFIG_HIGHMEM + if (PageHighMem(page)) + totalhigh_pages -= 1 << order; +#endif for (i = 0; i < (1 << order); i++) SetPageReserved((page+i)); pfn += (1 << order); -- 1.8.1.2
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