syzbot

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BUG: KCSAN: data-race in compact_zone / compact_zone

write to 0xffff88812fffcc10 of 8 bytes by task 6717 on cpu 0:
 update_cached_migrate mm/compaction.c:418 [inline]
 isolate_migratepages mm/compaction.c:1824 [inline]
 compact_zone+0x97f/0x1fc0 mm/compaction.c:2181
 compact_zone_order+0x1c0/0x220 mm/compaction.c:2323
 try_to_compact_pages+0x1b9/0x610 mm/compaction.c:2376
 __alloc_pages_direct_compact+0x80/0x150 mm/page_alloc.c:3959
 __alloc_pages_slowpath.constprop.0+0x203/0xd90 mm/page_alloc.c:4533
 __alloc_pages_nodemask+0x2bd/0x300 mm/page_alloc.c:4822
 __alloc_pages include/linux/gfp.h:504 [inline]
 __alloc_pages_node include/linux/gfp.h:517 [inline]
 alloc_pages_vma+0x29b/0x390 mm/mempolicy.c:2239
 do_huge_pmd_anonymous_page+0x2af/0x1000 mm/huge_memory.c:772
 create_huge_pmd mm/memory.c:4097 [inline]
 __handle_mm_fault+0x2d79/0x2ec0 mm/memory.c:4316
 handle_mm_fault+0x21c/0x540 mm/memory.c:4382
 do_user_addr_fault arch/x86/mm/fault.c:1464 [inline]
 do_page_fault+0x48a/0xa96 arch/x86/mm/fault.c:1535
 page_fault+0x34/0x40 arch/x86/entry/entry_64.S:1203

read to 0xffff88812fffcc10 of 8 bytes by task 6728 on cpu 1:
 update_cached_migrate mm/compaction.c:417 [inline]
 isolate_migratepages mm/compaction.c:1824 [inline]
 compact_zone+0x95b/0x1fc0 mm/compaction.c:2181
 compact_zone_order+0x1c0/0x220 mm/compaction.c:2323
 try_to_compact_pages+0x1b9/0x610 mm/compaction.c:2376
 __alloc_pages_direct_compact+0x80/0x150 mm/page_alloc.c:3959
 __alloc_pages_slowpath.constprop.0+0x203/0xd90 mm/page_alloc.c:4533
 __alloc_pages_nodemask+0x2bd/0x300 mm/page_alloc.c:4822
 __alloc_pages include/linux/gfp.h:504 [inline]
 __alloc_pages_node include/linux/gfp.h:517 [inline]
 alloc_pages_vma+0x29b/0x390 mm/mempolicy.c:2239
 do_huge_pmd_anonymous_page+0x2af/0x1000 mm/huge_memory.c:772
 create_huge_pmd mm/memory.c:4097 [inline]
 __handle_mm_fault+0x2d79/0x2ec0 mm/memory.c:4316
 handle_mm_fault+0x21c/0x540 mm/memory.c:4382
 do_user_addr_fault arch/x86/mm/fault.c:1464 [inline]
 do_page_fault+0x48a/0xa96 arch/x86/mm/fault.c:1535
 page_fault+0x34/0x40 arch/x86/entry/entry_64.S:1203

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 6728 Comm: syz-fuzzer Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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