3.19.8-ckt3 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Mel Gorman <[email protected]> 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 <[email protected]> Reported-by: Jovi Zhangwei <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Peter Zijlstra <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> [ kamal: backport to 3.19-stable ] Signed-off-by: Kamal Mostafa <[email protected]> --- 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 fe331fc..44cfeb3 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2162,8 +2162,10 @@ 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) || + (vma->vm_flags & VM_MIXEDMAP)) { continue; + } /* * Shared library pages mapped by multiple processes are not -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
