linux/kernel/sched
Mel Gorman 8e76d4eecf sched, numa: do not hint for NUMA balancing on VM_MIXEDMAP mappings
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@suse.de>
Reported-by: Jovi Zhangwei <jovi@cloudflare.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-10 16:43:43 -07:00
..
auto_group.c
auto_group.h
clock.c
completion.c
core.c Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2015-05-22 15:15:30 -07:00
cpuacct.c
cpuacct.h
cpudeadline.c
cpudeadline.h
cpupri.c
cpupri.h
cputime.c
deadline.c sched/deadline: Support DL task migration during CPU hotplug 2015-04-02 17:42:57 +02:00
debug.c sched: Track group sched_entity usage contributions 2015-03-27 09:35:58 +01:00
fair.c sched, numa: do not hint for NUMA balancing on VM_MIXEDMAP mappings 2015-06-10 16:43:43 -07:00
features.h
idle_task.c
idle.c cpuidle: Run tick_broadcast_exit() with disabled interrupts 2015-04-29 15:19:21 +02:00
Makefile
proc.c
rt.c sched/core: Remove unused argument from init_[rt|dl]_rq() 2015-04-02 17:42:55 +02:00
sched.h sched/core: Remove unused argument from init_[rt|dl]_rq() 2015-04-02 17:42:55 +02:00
stats.c
stats.h
stop_task.c
wait.c