WARNING: CPU: 2 PID: 23145 at mm/vmstat.c:986 __fragmentation_index caused by KVM

WARNING: CPU: 2 PID: 23145 at mm/vmstat.c:986 __fragmentation_index caused by KVM

[Eric Wheeler]

Hello all,

We are getting this warning in 4.14.13. Is this benign, or something we 
need to deal with?

~]# free -m
              total        used        free      shared  buff/cache   available
Mem:          64330       12841       49735          40        1754       50142
Swap:         19299           0       19299


[53421.567038] ------------[ cut here ]------------
[53421.572355] WARNING: CPU: 2 PID: 23145 at mm/vmstat.c:986 __fragmentation_index+0x55/0x60
[53421.577669] Modules linked in: btrfs xor zstd_decompress zstd_compress xxhash raid6_pq dm_crypt binfmt_misc dm_snapshot lz4 lz4_compress zram drbd lru_cache ebtable_filter ebtables ip6table_filter ip6_tables iptable_nat nf_nat_ipv4 nf_nat xt_connbytes xt_DSCP iptable_mangle ipt_REJECT nf_reject_ipv4 xt_limit nf_log_ipv4 nf_log_common xt_LOG nf_conntrack_ipv4 nf_defrag_ipv4 xt_comment xt_owner mpt3sas raid_class scsi_transport_sas mptctl mptbase xt_recent xt_conntrack nf_conntrack xt_set iptable_filter ip_set_hash_net ip_set nfnetlink netconsole dm_thin_pool dm_persistent_data dm_bio_prison dm_bufio libcrc32c 8021q garp mrp bridge stp llc sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass bcache crct10dif_pclmul crc32_pclmul iTCO_wdt iTCO_vendor_support ghash_
 clmulni_intel
[53421.615543]  mxm_wmi dcdbas pcspkr sg ipmi_si lpc_ich ipmi_devintf mfd_core ipmi_msghandler wmi mei_me mei shpchp acpi_power_meter nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables ext4 mbcache jbd2 mgag200 drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm igb crc32c_intel ptp drm pps_core dca megaraid_sas i2c_algo_bit i2c_core dm_mirror dm_region_hash dm_log dm_mod dax bonding
[53421.638163] CPU: 2 PID: 23145 Comm: qemu-kvm Tainted: G        W       4.14.13 #66
[53421.643753] Hardware name: Dell Inc. PowerEdge R730xd/0599V5, BIOS 2.7.0 12/005/2017
[53421.649442] task: ffff977749760000 task.stack: ffffa42a0d30c000
[53421.655112] RIP: 0010:__fragmentation_index+0x55/0x60
[53421.660574] RSP: 0018:ffffa42a0d30f940 EFLAGS: 00010202
[53421.666042] RAX: 000000000000000b RBX: 000000000000000b RCX: 000000000000000a
[53421.671576] RDX: ffffa42a0d30f948 RSI: ffffa42a0d30f948 RDI: 000000000000000b
[53421.677092] RBP: 0000000000000004 R08: 00000000000001d0 R09: 00000000000001f3
[53421.682579] R10: 0000000000074a88 R11: 0000000000074000 R12: ffff9777bffdd680
[53421.688175] R13: 000000000000000b R14: 0000000000000000 R15: ffffa42a0d30fa30
[53421.693674] FS:  00007f8d96e2b700(0000) GS:ffff9777bfc80000(0000) knlGS:0000000000000000
[53421.699285] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[53421.704797] CR2: 0000000000000000 CR3: 0000000fa550c001 CR4: 00000000001626e0
[53421.710283] Call Trace:
[53421.715728]  fragmentation_index+0x2e/0x50
[53421.721184]  compaction_suitable+0xa3/0xd0
[53421.726554]  shrink_node+0x268/0x320
[53421.731919]  node_reclaim+0x19d/0x250
[53421.737327]  get_page_from_freelist+0x16a/0xac0
[53421.742718]  ? ttwu_do_wakeup+0x19/0x140
[53421.748192]  ? __schedule+0x1e4/0x770
[53421.753673]  __alloc_pages_nodemask+0x107/0x290
[53421.759152]  kmalloc_large_node+0x31/0x50
[53421.764659]  __kmalloc_node+0x20a/0x260
[53421.770151]  kvmalloc_node+0x46/0x80
[53421.775540]  kvm_arch_create_memslot+0x58/0x1a0 [kvm]
[53421.776865]  __kvm_set_memory_region+0x725/0x860 [kvm]
[53421.777848]  kvm_set_memory_region+0x26/0x40 [kvm]
[53421.778508]  kvm_vm_ioctl+0x438/0x830 [kvm]
[53421.779159]  ? kvm_arch_vcpu_put+0xb4/0xd0 [kvm]
[53421.779857]  ? kvm_vcpu_ioctl+0x13c/0x5b0 [kvm]
[53421.780497]  ? do_sigtimedwait+0xcb/0x230
[53421.781126]  do_vfs_ioctl+0xa6/0x5f0
[53421.781734]  SyS_ioctl+0x74/0x80
[53421.782325]  do_syscall_64+0x61/0x1a0
[53421.782900]  entry_SYSCALL64_slow_path+0x25/0x25
[53421.783463] RIP: 0033:0x7f8da0a39107
[53421.784012] RSP: 002b:00007f8d96e2a698 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[53421.784576] RAX: ffffffffffffffda RBX: 000055827b03e0a0 RCX: 00007f8da0a39107
[53421.785104] RDX: 00007f8d96e2a700 RSI: 000000004020ae46 RDI: 000000000000000a
[53421.785631] RBP: 000055827b038000 R08: 000055827b041fa0 R09: 00000000000ec000
[53421.786141] R10: 00000000dff14000 R11: 0000000000000246 R12: 00007f8d96e2a700
[53421.786651] R13: 00000000e0000000 R14: 000055827b03e0a0 R15: 00000000000001fd
[53421.787143] Code: d2 45 89 c0 48 69 c0 e8 03 00 00 48 f7 f6 31 d2 48 05 e8 03 00 00 49 f7 f0 48 89 c1 b8 e8 03 00 00 29 c8 c3 b8 18 fc ff ff f3 c3 <0f> ff 31 c0 c3 66 0f 1f 44 00 00 0f 1f 44 00 00 41 57 b9 06 00 
kernel: ------------[ cut here ]------------

--
Eric Wheeler