1 files changed, 24 insertions, 0 deletions
diff --git a/etc/hyperthreading.sh b/etc/hyperthreading.sh
new file mode 100755
index 000000000..82603c5a3
--- /dev/null
+++ b/etc/hyperthreading.sh
@@ -0,0 +1,24 @@
+#!/bin/bash
+set -eu
+
+case $1 in
+   on)
+     for f in "/sys/devices/system/cpu/cpu"[0-9]*/online; do
+       echo 1 > "$f"
+     done
+     ;;
+  off)
+    cores=""
+    for cpu in "/sys/devices/system/cpu/cpu"[0-9]* ; do
+      if grep -vq '^1$' "$cpu/online" 2>/dev/null; then
+        continue
+      fi
+      coreid=$(cat "$cpu/topology/core_id")
+      if echo "$cores" | grep -- "$coreid" ; then
+        echo 0 > "$cpu/online"
+      fi
+      cores=$(printf "$cores\n$coreid")
+    done
+    ;;
+  *) echo "USAGE: hyperthreading.sh <on|off>"
+esac