Re: [libvirt] [PATCH v2 18/21] qemu: vcpu: Aggregate code to set vCPU tuning

Rather than iterating 3 times for various settings this function aggregates all the code into single place. One of the other advantages is that it can then be reused for properly setting vCPU info on hotplug.

--- src/qemu/qemu_cgroup.c | 95 --------------------- src/qemu/qemu_cgroup.h | 1 - src/qemu/qemu_process.c | 216 +++++++++++++++++++++++++++++++++--------------- src/qemu/qemu_process.h | 4 + 4 files changed, 152 insertions(+), 164 deletions(-)

@@ -4464,6 +4402,152 @@ qemuProcessInit(virQEMUDriverPtr driver, /** + * qemuProcessSetupVcpu: + * @vm: domain object + * @vcpuid: id of VCPU to set defaults + * + * This function sets resource properities (affinity, cgroups, scheduler) for a + * vCPU. This function expects that the vCPU is online and the vCPU pids were + * correctly detected at the point when it's called. + * + * Returns 0 on success, -1 on error. + */ +int +qemuProcessSetupVcpu(virDomainObjPtr vm, + unsigned int vcpuid) +{ + pid_t vcpupid = qemuDomainGetVcpuPid(vm, vcpuid); + virDomainVcpuInfoPtr vcpu = virDomainDefGetVcpu(vm->def, vcpuid); + qemuDomainObjPrivatePtr priv = vm->privateData; + char *mem_mask = NULL; + virDomainNumatuneMemMode mem_mode; + unsigned long long period = vm->def->cputune.period; + long long quota = vm->def->cputune.quota; + virCgroupPtr cgroup_vcpu = NULL; + virBitmapPtr cpumask; + int ret = -1; + + if (period || quota) { + if (virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_CPU)) {

+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("cgroup cpu is required for scheduler tuning")); + goto cleanup; + } + } + + if (virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_CPU) || + virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_CPUSET)) { + + if (virDomainNumatuneGetMode(vm->def->numa, -1, &mem_mode) == 0 && + mem_mode == VIR_DOMAIN_NUMATUNE_MEM_STRICT && + virDomainNumatuneMaybeFormatNodeset(vm->def->numa, + priv->autoNodeset, + &mem_mask, -1) < 0) + goto cleanup; + + if (virCgroupNewThread(priv->cgroup, VIR_CGROUP_THREAD_VCPU, vcpuid, + true, &cgroup_vcpu) < 0) + goto cleanup; + + if (period || quota) { + if (qemuSetupCgroupVcpuBW(cgroup_vcpu, period, quota) < 0) + goto cleanup; + } + } + + /* infer which cpumask shall be used */ + if (vcpu->cpumask) + cpumask = vcpu->cpumask; + else if (vm->def->placement_mode == VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO) + cpumask = priv->autoCpuset; + else + cpumask = vm->def->cpumask; + + if (cpumask) { + /* setup legacy affinty */ + if (virProcessSetAffinity(vcpupid, cpumask) < 0) + goto cleanup; +

+ /* setup cgroups */