From: Zhou yimin <zhouyimin(a)huawei.com&gt; If VM is configured with many devices(including passthrough devices) and large memory, libvirtd will take seconds(in the worst case) to wait for monitor. In this period the qemu process may run on any PCPU though I intend to pin emulator to the specified PCPU in xml configuration. Actually qemu process takes high cpu usage during vm startup. So this is not the strict CPU isolation in this case. Signed-off-by: Zhou yimin <zhouyimin(a)huawei.com&gt; --- src/qemu/qemu_process.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 95548aa..ef258cf 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -4553,6 +4553,14 @@ int qemuProcessStart(virConnectPtr conn, if (ret == -1) /* The VM failed to start */ goto cleanup; + VIR_DEBUG("Setting cgroup for emulator (if required)"); + if (qemuSetupCgroupForEmulator(driver, vm, nodemask) < 0) + goto cleanup; + + VIR_DEBUG("Setting affinity of emulator threads"); + if (qemuProcessSetEmulatorAffinity(vm) < 0) + goto cleanup; + VIR_DEBUG("Waiting for monitor to show up"); if (qemuProcessWaitForMonitor(driver, vm, asyncJob, priv->qemuCaps, pos) < 0) goto cleanup; @@ -4588,10 +4596,6 @@ int qemuProcessStart(virConnectPtr conn, if (qemuSetupCgroupForVcpu(vm) < 0) goto cleanup; - VIR_DEBUG("Setting cgroup for emulator (if required)"); - if (qemuSetupCgroupForEmulator(driver, vm, nodemask) < 0) - goto cleanup; - VIR_DEBUG("Setting cgroup for each IOThread (if required)"); if (qemuSetupCgroupForIOThreads(vm) < 0) goto cleanup; @@ -4600,10 +4604,6 @@ int qemuProcessStart(virConnectPtr conn, if (qemuProcessSetVcpuAffinities(vm) < 0) goto cleanup; - VIR_DEBUG("Setting affinity of emulator threads"); - if (qemuProcessSetEmulatorAffinity(vm) < 0) - goto cleanup; - VIR_DEBUG("Setting affinity of IOThread threads"); if (qemuProcessSetIOThreadsAffinity(vm) < 0) goto cleanup; -- 1.7.12.4