From: Jiang Biao <jiang.biao2@xxxxxxxxxx>
When order is -1 or too big, *1UL << order* will be 0, which will
cause divide error like this,
divide error: 0000 [#1] SMP
Call Trace:
[<ffffffff81168423>] compaction_suitable+0x63/0xc0
[<ffffffff81168a75>] compact_zone+0x35/0x950
[<ffffffff811745b5>] ? free_percpu+0xb5/0x140
[<ffffffff81092b23>] ? schedule_on_each_cpu+0x133/0x160
[<ffffffff8116949c>] compact_node+0x10c/0x120
[<ffffffff8116953c>] sysctl_compaction_handler+0x5c/0x90
[<ffffffff811fa517>] proc_sys_call_handler+0x97/0xd0
[<ffffffff811fa564>] proc_sys_write+0x14/0x20
[<ffffffff81187368>] vfs_write+0xb8/0x1a0
[<ffffffff81187c61>] sys_write+0x51/0x90
[<ffffffff8100b052>] system_call_fastpath+0x16/0x1b
Signed-off-by: Wen Yang <wen.yang99@xxxxxxxxxx>
Reviewed-by: Jiang Biao <jiang.biao2@xxxxxxxxxx>
---
mm/vmstat.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 76f7367..2f9d012 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -870,6 +870,9 @@ static int __fragmentation_index(unsigned int order, struct contig_page_info *in
{
unsigned long requested = 1UL << order;
+ if (!requested)
+ return 0;
+
if (!info->free_blocks_total)
return 0;
--
2.7.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
