I'm also curious why you decided to omit the hugepages setup from the original script.
EDIT: I found a solution, which I posted here.
]]>I've changed the name of the script from cset.sh to 'qemu'(before qemu was a folder) on the /etc/libvirt/hooks and now is working.
]]> cset: Cpuset (cset) 1.6
Maybe someone knows how to run hooks under libvirt?
I tried with these locations:
/etc/libvirt/hooks
/etc/libvirt/hooks/cset.sh
/etc/libvirt/hooks/qemu
/etc/libvirt/hooks/qemu.d
/etc/libvirt/hooks/qemu/cset.sh
/etc/libvirt/hooks/qemu/win10
/etc/libvirt/hooks/qemu/win10/prepare
/etc/libvirt/hooks/qemu/win10/release
/etc/libvirt/hooks/qemu/win10/prepare/begin
/etc/libvirt/hooks/qemu/win10/prepare/begin/cset.sh
/etc/libvirt/hooks/qemu/win10/release/end
/etc/libvirt/hooks/qemu/win10/release/end/cset.sh
/etc/libvirt/hooks/qemu.d/win10
/etc/libvirt/hooks/qemu.d/win10/prepare
/etc/libvirt/hooks/qemu.d/win10/release
/etc/libvirt/hooks/qemu.d/win10/prepare/begin
/etc/libvirt/hooks/qemu.d/win10/prepare/begin/cset.sh
/etc/libvirt/hooks/qemu.d/win10/release/end
/etc/libvirt/hooks/qemu.d/win10/release/end/cset.sh
The script which I use:
#!/usr/bin/env bash
#
# Original author: Rokas Kupstys <rokups@zoho.com>
# Heavily modified by: Danny Lin <danny@kdrag0n.dev>
#
# This hook uses the `cset` tool to dynamically isolate and unisolate CPUs using
# the kernel's cgroup cpusets feature. While it's not as effective as
# full kernel-level scheduler and timekeeping isolation, it still does wonders
# for VM latency as compared to not isolating CPUs at all. Note that vCPU thread
# affinity is a must for this to work properly.
#
# Original source: https://rokups.github.io/#!pages/gaming-vm-performance.md
#
# Target file locations:
# - $SYSCONFDIR/hooks/qemu.d/vm_name/prepare/begin/cset.sh
# - $SYSCONFDIR/hooks/qemu.d/vm_name/release/end/cset.sh
# $SYSCONFDIR is usually /etc/libvirt.
#
TOTAL_CORES='0-7'
TOTAL_CORES_MASK=FF # 0-7, bitmask 0b11111111
HOST_CORES='0,4' # Cores reserved for host
HOST_CORES_MASK=11 # 0,4, bitmask 0b00010001
VIRT_CORES='1-3,5-7' # Cores reserved for virtual machine(s)
VM_NAME="$1"
VM_ACTION="$2/$3"
function shield_vm() {
cset -m set -c $TOTAL_CORES -s machine.slice
cset -m shield --kthread on --cpu $VIRT_CORES
}
function unshield_vm() {
cset -m shield --reset
}
# For convenient manual invocation
if [[ "$VM_NAME" == "shield" ]]; then
shield_vm
exit
elif [[ "$VM_NAME" == "unshield" ]]; then
unshield_vm
exit
fi
if [[ "$VM_ACTION" == "prepare/begin" ]]; then
echo "libvirt-qemu cset: Reserving CPUs $VIRT_CORES for VM $VM_NAME" > /dev/kmsg 2>&1
shield_vm > /dev/kmsg 2>&1
# the kernel's dirty page writeback mechanism uses kthread workers. They introduce
# massive arbitrary latencies when doing disk writes on the host and aren't
# migrated by cset. Restrict the workqueue to use only cpu 0.
echo $HOST_CORES_MASK > /sys/bus/workqueue/devices/writeback/cpumask
echo 0 > /sys/bus/workqueue/devices/writeback/numa
echo "libvirt-qemu cset: Successfully reserved CPUs $VIRT_CORES" > /dev/kmsg 2>&1
elif [[ "$VM_ACTION" == "release/end" ]]; then
echo "libvirt-qemu cset: Releasing CPUs $VIRT_CORES from VM $VM_NAME" > /dev/kmsg 2>&1
unshield_vm > /dev/kmsg 2>&1
# Revert changes made to the writeback workqueue
echo $TOTAL_CORES_MASK > /sys/bus/workqueue/devices/writeback/cpumask
echo 1 > /sys/bus/workqueue/devices/writeback/numa
echo "libvirt-qemu cset: Successfully released CPUs $VIRT_CORES" > /dev/kmsg 2>&1
fi