==================================================================
BUG: KCSAN: data-race in get_scan_count / mem_cgroup_update_lru_size

write to 0xffff88812bd0f9f8 of 8 bytes by task 22888 on cpu 1:
 mem_cgroup_update_lru_size+0x53/0xf0 mm/memcontrol.c:1275
 update_lru_size include/linux/mm_inline.h:44 [inline]
 add_page_to_lru_list include/linux/mm_inline.h:51 [inline]
 __pagevec_lru_add_fn+0x39e/0x570 mm/swap.c:1019
 pagevec_lru_move_fn+0xff/0x190 mm/swap.c:227
 __pagevec_lru_add mm/swap.c:1029 [inline]
 lru_cache_add+0x132/0x180 mm/swap.c:473
 add_to_page_cache_lru+0x150/0x1b0 mm/filemap.c:934
 page_cache_readahead_unbounded+0x234/0x440 mm/readahead.c:228
 __do_page_cache_readahead+0x96/0xb0 mm/readahead.c:273
 ra_submit mm/internal.h:64 [inline]
 do_sync_mmap_readahead mm/filemap.c:2424 [inline]
 filemap_fault+0x63d/0x11e0 mm/filemap.c:2510
 ext4_filemap_fault+0x4b/0x60 fs/ext4/inode.c:6060
 __do_fault mm/memory.c:3464 [inline]
 do_read_fault+0x41f/0x730 mm/memory.c:3857
 do_fault mm/memory.c:3985 [inline]
 handle_pte_fault mm/memory.c:4225 [inline]
 __handle_mm_fault mm/memory.c:4357 [inline]
 handle_mm_fault+0x135d/0x1930 mm/memory.c:4394
 do_user_addr_fault+0x393/0x810 arch/x86/mm/fault.c:1295
 handle_page_fault arch/x86/mm/fault.c:1365 [inline]
 exc_page_fault+0xb8/0x330 arch/x86/mm/fault.c:1418
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:544

read to 0xffff88812bd0f9f8 of 8 bytes by task 2462 on cpu 0:
 mem_cgroup_get_zone_lru_size include/linux/memcontrol.h:523 [inline]
 lruvec_lru_size mm/vmscan.c:332 [inline]
 get_scan_count+0x2b3/0x770 mm/vmscan.c:2333
 shrink_lruvec+0x5a/0x620 mm/vmscan.c:2437
 shrink_node_memcgs+0x1be/0x360 mm/vmscan.c:2656
 shrink_node+0x94e/0x1170 mm/vmscan.c:2770
 kswapd_shrink_node mm/vmscan.c:3517 [inline]
 balance_pgdat+0x675/0xbb0 mm/vmscan.c:3675
 kswapd+0x1ef/0x370 mm/vmscan.c:3932
 kthread+0x20d/0x230 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2462 Comm: kswapd0 Not tainted 5.8.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================