==================================================================
BUG: KCSAN: data-race in compact_zone / compact_zone

write to 0xffff88813fffbc10 of 8 bytes by task 9856 on cpu 0:
 update_cached_migrate mm/compaction.c:435 [inline]
 isolate_migratepages mm/compaction.c:1887 [inline]
 compact_zone+0x1397/0x1d30 mm/compaction.c:2334
 compact_zone_order mm/compaction.c:2477 [inline]
 try_to_compact_pages+0x307/0x800 mm/compaction.c:2535
 __alloc_pages_direct_compact+0x89/0x350 mm/page_alloc.c:4147
 __alloc_pages_slowpath+0x5b1/0x9c0 mm/page_alloc.c:4808
 __alloc_pages_nodemask+0x269/0x350 mm/page_alloc.c:5012
 __alloc_pages include/linux/gfp.h:511 [inline]
 __alloc_pages_node include/linux/gfp.h:524 [inline]
 alloc_pages_vma+0x718/0x890 mm/mempolicy.c:2211
 do_huge_pmd_anonymous_page+0x643/0x940 mm/huge_memory.c:761
 create_huge_pmd mm/memory.c:4269 [inline]
 __handle_mm_fault mm/memory.c:4493 [inline]
 handle_mm_fault+0x11fb/0x17b0 mm/memory.c:4620
 faultin_page mm/gup.c:851 [inline]
 __get_user_pages+0xa32/0xff0 mm/gup.c:1070
 __get_user_pages_locked mm/gup.c:1256 [inline]
 __get_user_pages_remote+0x226/0x6e0 mm/gup.c:1723
 pin_user_pages_remote+0x58/0x80 mm/gup.c:2791
 process_vm_rw_single_vec+0x178/0x460 mm/process_vm_access.c:106
 process_vm_rw_core mm/process_vm_access.c:216 [inline]
 process_vm_rw+0x3a3/0x540 mm/process_vm_access.c:284
 __do_sys_process_vm_writev mm/process_vm_access.c:304 [inline]
 __se_sys_process_vm_writev mm/process_vm_access.c:299 [inline]
 __x64_sys_process_vm_writev+0x76/0x90 mm/process_vm_access.c:299
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88813fffbc10 of 8 bytes by task 9859 on cpu 1:
 update_cached_migrate mm/compaction.c:434 [inline]
 isolate_migratepages mm/compaction.c:1887 [inline]
 compact_zone+0x1373/0x1d30 mm/compaction.c:2334
 compact_zone_order mm/compaction.c:2477 [inline]
 try_to_compact_pages+0x307/0x800 mm/compaction.c:2535
 __alloc_pages_direct_compact+0x89/0x350 mm/page_alloc.c:4147
 __alloc_pages_slowpath+0x5b1/0x9c0 mm/page_alloc.c:4808
 __alloc_pages_nodemask+0x269/0x350 mm/page_alloc.c:5012
 __alloc_pages include/linux/gfp.h:511 [inline]
 __alloc_pages_node include/linux/gfp.h:524 [inline]
 alloc_pages_vma+0x718/0x890 mm/mempolicy.c:2211
 do_huge_pmd_anonymous_page+0x643/0x940 mm/huge_memory.c:761
 create_huge_pmd mm/memory.c:4269 [inline]
 __handle_mm_fault mm/memory.c:4493 [inline]
 handle_mm_fault+0x11fb/0x17b0 mm/memory.c:4620
 faultin_page mm/gup.c:851 [inline]
 __get_user_pages+0xa32/0xff0 mm/gup.c:1070
 __get_user_pages_locked mm/gup.c:1256 [inline]
 __get_user_pages_remote+0x226/0x6e0 mm/gup.c:1723
 pin_user_pages_remote+0x58/0x80 mm/gup.c:2791
 process_vm_rw_single_vec+0x178/0x460 mm/process_vm_access.c:106
 process_vm_rw_core mm/process_vm_access.c:216 [inline]
 process_vm_rw+0x3a3/0x540 mm/process_vm_access.c:284
 __do_sys_process_vm_writev mm/process_vm_access.c:304 [inline]
 __se_sys_process_vm_writev mm/process_vm_access.c:299 [inline]
 __x64_sys_process_vm_writev+0x76/0x90 mm/process_vm_access.c:299
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 9859 Comm: syz-executor.2 Not tainted 5.11.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================