====== 13 CentOS Meltdown CPU ======

CPU脆弱性対策無効化
<code>
echo 0 > /sys/kernel/debug/x86/pti_enabled
echo 0 > /sys/kernel/debug/x86/retp_enabled
echo 0 > /sys/kernel/debug/x86/ibrs_enabled
</code>


===== Unixbenchの実行結果 =====

同じCPU「Intel(R) Xeon(R) CPU           E5645  @ 2.40GHz」でもKernelによって、だいぶスコアが違う
※1コアで計測

<code>
→3.10.0-123.el7.x86_64
System Benchmarks Index Score                                        1568.0

→3.10.0-229.1.2.el7.centos.plus.x86_64
System Benchmarks Index Score                                        1613.6

→3.10.0-693.11.6.el7.centos.plus.x86_64 →×
System Benchmarks Index Score                                         500.3

  ↓ptiのみ
System Benchmarks Index Score                                         538.4

  ↓pti,retp,ibrs
System Benchmarks Index Score                                        1245.4
</code>

{{tag>CentOS7 CPU}}