==================================================================
BUG: KCSAN: data-race in lru_add_drain_all / mark_page_accessed

write to 0xffff88813bd27750 of 1 bytes by task 16415 on cpu 1:
 pagevec_add include/linux/pagevec.h:74 [inline]
 activate_page mm/swap.c:346 [inline]
 mark_page_accessed+0x386/0x5f0 mm/swap.c:431
 zap_pte_range+0x4f8/0x13f0 mm/memory.c:1267
 zap_pmd_range mm/memory.c:1374 [inline]
 zap_pud_range mm/memory.c:1403 [inline]
 zap_p4d_range mm/memory.c:1424 [inline]
 unmap_page_range+0x540/0x650 mm/memory.c:1445
 unmap_single_vma+0x157/0x210 mm/memory.c:1490
 unmap_vmas+0xc0/0x170 mm/memory.c:1522
 unmap_region+0x136/0x1d0 mm/mmap.c:2674
 __do_munmap+0xed2/0x1390 mm/mmap.c:2906
 do_munmap mm/mmap.c:2917 [inline]
 munmap_vma_range mm/mmap.c:598 [inline]
 mmap_region+0x58a/0x1480 mm/mmap.c:1750
 do_mmap+0x77d/0xc90 mm/mmap.c:1581
 vm_mmap_pgoff+0xf7/0x1d0 mm/util.c:519
 ksys_mmap_pgoff+0xe1/0x380 mm/mmap.c:1632
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88813bd27750 of 1 bytes by task 1630 on cpu 0:
 pagevec_count include/linux/pagevec.h:61 [inline]
 need_activate_page_drain mm/swap.c:334 [inline]
 lru_add_drain_all+0x216/0x3c0 mm/swap.c:818
 khugepaged_do_scan+0x47/0x330 mm/khugepaged.c:2213
 khugepaged+0x75/0x680 mm/khugepaged.c:2274
 kthread+0x20b/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1630 Comm: khugepaged Not tainted 5.12.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================