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BUG: KCSAN: data-race in mem_cgroup_protected / mem_cgroup_protected

write to 0xffff8880afcf0138 of 8 bytes by task 12152 on cpu 1:
 mem_cgroup_protected+0x236/0x2a0 mm/memcontrol.c:6432
 shrink_node+0x21e/0xb30 mm/vmscan.c:2777
 shrink_zones mm/vmscan.c:3027 [inline]
 do_try_to_free_pages+0x242/0x940 mm/vmscan.c:3085
 try_to_free_pages+0x1ed/0x4a0 mm/vmscan.c:3298
 __perform_reclaim mm/page_alloc.c:4121 [inline]
 __alloc_pages_direct_reclaim mm/page_alloc.c:4142 [inline]
 __alloc_pages_slowpath+0x45c/0xee0 mm/page_alloc.c:4559
 __alloc_pages_nodemask+0x2c8/0x310 mm/page_alloc.c:4773
 alloc_pages_current+0xd1/0x170 mm/mempolicy.c:2188
 alloc_pages include/linux/gfp.h:509 [inline]
 relay_alloc_buf kernel/relay.c:136 [inline]
 relay_create_buf kernel/relay.c:177 [inline]
 relay_open_buf.part.0+0x219/0x600 kernel/relay.c:452
 relay_open_buf kernel/relay.c:449 [inline]
 relay_open kernel/relay.c:599 [inline]
 relay_open+0x381/0x5e0 kernel/relay.c:563
 do_blk_trace_setup+0x2aa/0x5f0 kernel/trace/blktrace.c:526
 __blk_trace_setup+0x81/0x110 kernel/trace/blktrace.c:571
 blk_trace_setup+0x56/0x80 kernel/trace/blktrace.c:589
 sg_ioctl+0x117d/0x1520 drivers/scsi/sg.c:1112
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x991/0xc60 fs/ioctl.c:696

write to 0xffff8880afcf0138 of 8 bytes by task 1767 on cpu 0:
 mem_cgroup_protected+0x236/0x2a0 mm/memcontrol.c:6432
 shrink_node+0x21e/0xb30 mm/vmscan.c:2777
 kswapd_shrink_node mm/vmscan.c:3549 [inline]
 balance_pgdat+0x60e/0xbf0 mm/vmscan.c:3707
 kswapd+0x35b/0x800 mm/vmscan.c:3958
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1767 Comm: kswapd0 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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