[added to the 3.18 stable tree] sched, numa: Do not hint for NUMA balancing on VM_MIXEDMAP mappings

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Mel Gorman <mgorman@xxxxxxx>

commit 8e76d4eecf7afeec9328e21cd5880e281838d0d6 upstream.

Jovi Zhangwei reported the following problem

  Below kernel vm bug can be triggered by tcpdump which mmaped a lot of pages
  with GFP_COMP flag.

  [Mon May 25 05:29:33 2015] page:ffffea0015414000 count:66 mapcount:1 mapping:          (null) index:0x0
  [Mon May 25 05:29:33 2015] flags: 0x20047580004000(head)
  [Mon May 25 05:29:33 2015] page dumped because: VM_BUG_ON_PAGE(compound_order(page) && !PageTransHuge(page))
  [Mon May 25 05:29:33 2015] ------------[ cut here ]------------
  [Mon May 25 05:29:33 2015] kernel BUG at mm/migrate.c:1661!
  [Mon May 25 05:29:33 2015] invalid opcode: 0000 [#1] SMP

In this case it was triggered by running tcpdump but it's not necessary
reproducible on all systems.

  sudo tcpdump -i bond0.100 'tcp port 4242' -c 100000000000 -w 4242.pcap

Compound pages cannot be migrated and it was not expected that such pages
be marked for NUMA balancing.  This did not take into account that drivers
such as net/packet/af_packet.c may insert compound pages into userspace
with vm_insert_page.  This patch tells the NUMA balancing protection
scanner to skip all VM_MIXEDMAP mappings which avoids the possibility that
compound pages are marked for migration.

Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
Reported-by: Jovi Zhangwei <jovi@xxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
[jovi: Backported to 3.18: adjust context]
Signed-off-by: Jovi Zhangwei <jovi@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
---
 kernel/sched/fair.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index ef2b104..2246a36 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1979,8 +1979,10 @@ void task_numa_work(struct callback_head *work)
 		vma = mm->mmap;
 	}
 	for (; vma; vma = vma->vm_next) {
-		if (!vma_migratable(vma) || !vma_policy_mof(vma))
+		if (!vma_migratable(vma) || !vma_policy_mof(vma) ||
+		    is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_MIXEDMAP)) {
 			continue;
+		}
 
 		/*
 		 * Shared library pages mapped by multiple processes are not
-- 
2.1.0

--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]