# Helpers for get_possible_cpus.
function get_possible_cpus_count_from_sysfs_possible_mask()
{
- local max_possible_cpu_id=$(cut -d '-' -f 2 < /sys/devices/system/cpu/possible)
- echo $((max_possible_cpu_id+1))
+ local max_possible_cpu_id
+
+ # The Awk script extracts the highest CPU id from the possible CPU
+ # mask. Assuming a numerical order, a field separator '-' and a record
+ # separator ','. The last value parsed is the highest id.
+ if [ -f /sys/devices/system/cpu/possible ]; then
+ max_possible_cpu_id=$(awk -F '-' 'BEGIN { RS = ","} { last = $NF } END { printf("%d\n", last) }' \
+ /sys/devices/system/cpu/possible)
+ echo "$((max_possible_cpu_id+1))"
+ else
+ echo "0"
+ fi
}
+# This is a fallback if the possible CPU mask is not available. This will not
+# take into account unplugged CPUs.
function get_max_cpus_count_from_sysfs_cpu_directories()
{
- local max_possible_cpu_id= \
- $(find /sys/devices/system/cpu/ -mindepth 1 -maxdepth 1 -regex ".+cpu[0-9]+" | \
- sed -e 's/cpu//g' | \
- awk -F '/' '{ if ($NF > N) N = $NF } END { print N }')
- echo $((max_possible_cpu_id+1))
+ local max_possible_cpu_id=0
+ local current_cpu_id
+
+ for i in /sys/devices/system/cpu/cpu[0-9]*; do
+ current_cpu_id="${i#/sys/devices/system/cpu/cpu}"
+ if [ "$current_cpu_id" -gt "$max_possible_cpu_id" ]; then
+ max_possible_cpu_id="$current_cpu_id"
+ fi
+ done
+
+ echo "$((max_possible_cpu_id+1))"
}
# Return the number of possible CPUs.
function get_possible_cpus_count()
{
- local possible_cpus_count=$(get_possible_cpus_count_from_sysfs_possible_mask)
+ local possible_cpus_count
+ possible_cpus_count=$(get_possible_cpus_count_from_sysfs_possible_mask)
- if [ $? -ne 0 ]; then
+ if [ "$possible_cpus_count" -eq "0" ]; then
+ local configured_cpus_count
+ configured_cpus_count=$(getconf _NPROCESSORS_CONF)
possible_cpus_count=$(get_max_cpus_count_from_sysfs_cpu_directories)
- local configured_cpus_count=$(getconf _NPROCESSORS_CONF)
- possible_cpus_count=$(($configured_cpus_count > $possible_cpus_count \
- ? $configured_cpus_count \
- : $possible_cpus_count))
+ possible_cpus_count=$((configured_cpus_count > possible_cpus_count \
+ ? configured_cpus_count \
+ : possible_cpus_count))
fi
- echo $possible_cpus_count
+ echo "$possible_cpus_count"
+}
+
+# Return the list of exposed CPU.
+#
+# NOTE! Use it like so:
+#
+# IFS=" " read -r -a VARIABLE <<< "$(get_exposed_cpus_list)"
+function get_exposed_cpus_list()
+{
+ local list=()
+
+ for i in /sys/devices/system/cpu/cpu[0-9]*; do
+ list+=("${i#/sys/devices/system/cpu/cpu}")
+ done
+
+ echo "${list[@]}"
}
# Return the number of _configured_ CPUs.