Решил посмотреть kern.log своего сервера, давно туда не заглядывал. И обнаружил в нем кучу записей вида
Jun 29 08:46:27 host kernel: [935431.943122] spurious APIC interrupt on CPU#0, should never happen.
Jun 29 08:47:28 host kernel: [935492.018795] spurious APIC interrupt on CPU#1, should never happen.
Jun 29 08:48:03 host kernel: [935527.477624] spurious APIC interrupt on CPU#1, should never happen.
Jun 29 08:48:34 host kernel: [935558.412969] spurious APIC interrupt on CPU#5, should never happen.
Jun 29 08:48:58 host kernel: [935582.311712] spurious APIC interrupt on CPU#4, should never happen.
Jun 29 08:48:58 host kernel: [935582.436498] spurious APIC interrupt on CPU#4, should never happen.
Jun 29 08:49:00 host kernel: [935584.737174] spurious APIC interrupt on CPU#1, should never happen.
Jun 29 08:49:00 host kernel: [935584.842413] spurious APIC interrupt on CPU#1, should never happen.
Jun 29 08:50:04 host kernel: [935648.508722] spurious APIC interrupt on CPU#3, should never happen.
Jun 29 08:50:17 host kernel: [935661.949842] spurious APIC interrupt on CPU#4, should never happen.
Jun 29 08:51:05 host kernel: [935709.406834] spurious APIC interrupt on CPU#4, should never happen.
Jun 29 08:51:25 host kernel: [935729.107920] spurious APIC interrupt on CPU#2, should never happen.
Jun 29 08:51:42 host kernel: [935746.611132] spurious APIC interrupt on CPU#3, should never happen.
Jun 29 08:51:43 host kernel: [935747.396060] spurious APIC interrupt on CPU#5, should never happen.
Jun 29 08:53:02 host kernel: [935826.186878] spurious APIC interrupt on CPU#3, should never happen.
Jun 29 08:53:02 host kernel: [935826.202413] spurious APIC interrupt on CPU#3, should never happen.
Jun 29 08:53:02 host kernel: [935826.264826] spurious APIC interrupt on CPU#3, should never happen.
Jun 29 08:54:04 host kernel: [935888.308779] spurious APIC interrupt on CPU#4, should never happen.
Jun 29 08:55:01 host kernel: [935945.955581] spurious APIC interrupt on CPU#1, should never happen.
Jun 29 08:55:32 host kernel: [935976.727019] spurious APIC interrupt on CPU#1, should never happen.
Jun 29 08:55:50 host kernel: [935994.448645] spurious APIC interrupt on CPU#6, should never happen.
Jun 29 08:56:01 host kernel: [936005.743055] spurious APIC interrupt on CPU#0, should never happen.
Jun 29 08:56:29 host kernel: [936033.074285] spurious APIC interrupt on CPU#5, should never happen.
Jun 29 08:57:02 host kernel: [936066.910721] spurious APIC interrupt on CPU#6, should never happen.
Jun 29 08:57:04 host kernel: [936068.689114] spurious APIC interrupt on CPU#4, should never happen.
Jun 29 08:57:04 host kernel: [936068.845115] spurious APIC interrupt on CPU#4, should never happen.
Jun 29 08:57:20 host kernel: [936083.977149] spurious APIC interrupt on CPU#4, should never happen.
Jun 29 08:58:50 host kernel: [936174.114072] spurious APIC interrupt on CPU#0, should never happen.
Jun 29 08:58:50 host kernel: [936174.752811] spurious APIC interrupt on CPU#0, should never happen.
Jun 29 08:59:13 host kernel: [936197.623301] spurious APIC interrupt on CPU#3, should never happen.
Jun 29 09:00:02 host kernel: imklog 5.8.11, log source = /proc/kmsg started.
Jun 29 09:00:04 host kernel: [936248.572948] spurious APIC interrupt on CPU#2, should never happen.
Jun 29 09:00:12 host kernel: [936256.607003] spurious APIC interrupt on CPU#0, should never happen.
Jun 29 09:00:13 host kernel: [936257.854980] spurious APIC interrupt on CPU#5, should never happen.
Jun 29 09:00:15 host kernel: [936258.993760] spurious APIC interrupt on CPU#5, should never happen.
Jun 29 09:01:39 host kernel: [936343.000600] spurious APIC interrupt on CPU#7, should never happen.
Jun 29 09:02:04 host kernel: [936368.006702] spurious APIC interrupt on CPU#1, should never happen.
Jun 29 09:02:45 host kernel: [936409.485060] spurious APIC interrupt on CPU#7, should never happen.
Jun 29 09:02:53 host kernel: [936417.741758] spurious APIC interrupt on CPU#3, should never happen.
Jun 29 09:03:42 host kernel: [936466.435950] spurious APIC interrupt on CPU#0, should never happen.
Jun 29 09:04:02 host kernel: [936486.520072] spurious APIC interrupt on CPU#6, should never happen.
Не могу понять что это обозначает, что ему не так.