On 07/18/2011 07:46 PM, Wen Congyang wrote:
> At 07/19/2011 04:35 AM, Adam Litke Write:
>> This is looking good to me. I am pleased to see that the global case is
>> handled as expected when per-vcpu threads are not active.
>>
>> On 07/18/2011 04:42 AM, Wen Congyang wrote:
>> <snip>
>>> +int qemuSetupCgroupForVcpu(struct qemud_driver *driver, virDomainObjPtr vm)
>>> +{
>>> + virCgroupPtr cgroup = NULL;
>>> + virCgroupPtr cgroup_vcpu = NULL;
>>> + qemuDomainObjPrivatePtr priv = vm->privateData;
>>> + int rc;
>>> + unsigned int i;
>>> + unsigned long long period = vm->def->cputune.period;
>>> + long long quota = vm->def->cputune.quota;
>>> +
>>> + if (driver->cgroup == NULL)
>>> + return 0; /* Not supported, so claim success */
>>
>> I just want to check: Is the above logic still valid? Failure to apply
>
> This logic is the same as the logic in the similar function qemuSetupCgroup().
Yes, I am aware. However, the introduction of cpu quotas is a major
feature that defines the amount of computing capacity a domain has
available. In my opinion, if a domain XML file specifies a quota then
'virsh create' should fail of that quota cannot be set up for any reason.
>
>> a quota setting (>0) could have fairly substantial implications for
>> system performance. I am not convinced either way but I do think this
>> point merits some discussion.
>>
>>> +
>>> + rc = virCgroupForDomain(driver->cgroup, vm->def->name, &cgroup, 0);
>>> + if (rc != 0) {
>>> + virReportSystemError(-rc,
>>> + _("Unable to find cgroup for %s"),
>>> + vm->def->name);
>>> + goto cleanup;
>>> + }
>>> +
>>> + if (priv->nvcpupids == 0 || priv->vcpupids[0] == vm->pid) {
>>> + /* If we does not know VCPU<->PID mapping or all vcpu runs in the same
>>> + * thread, we can not control each vcpu.
>>> + */
>>> + if (period || quota) {
>>> + if (qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_CPU)) {
>>> + if (qemuSetupCgroupVcpuBW(cgroup, period, quota) < 0)
>>> + goto cleanup;
>>> + }
>>> + }
>>> + return 0;
>>> + }
>>> +
>>> + for (i = 0; i < priv->nvcpupids; i++) {
>>> + rc = virCgroupForVcpu(cgroup, i, &cgroup_vcpu, 1);
>>> + if (rc < 0) {
>>> + virReportSystemError(-rc,
>>> + _("Unable to create vcpu cgroup for %s(vcpu:"
>>> + " %d)"),
>>> + vm->def->name, i);
>>> + goto cleanup;
>>> + }
>>> +
>>> + /* move the thread for vcpu to sub dir */
>>> + rc = virCgroupAddTask(cgroup_vcpu, priv->vcpupids[i]);
>>> + if (rc < 0) {
>>> + virReportSystemError(-rc,
>>> + _("unable to add vcpu %d task %d to cgroup"),
>>> + i, priv->vcpupids[i]);
>>> + goto cleanup;
>>> + }
>>> +
>>> + if (period || quota) {
>>> + if (qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_CPU)) {
>>> + if (qemuSetupCgroupVcpuBW(cgroup_vcpu, period, quota) < 0)
>>> + goto cleanup;
>>> + }
>>> + }
>>> +
>>> + virCgroupFree(&cgroup_vcpu);
>>> + }
>>> +
>>> + virCgroupFree(&cgroup_vcpu);
>>> + virCgroupFree(&cgroup);
>>> + return 0;
>>> +
>>> +cleanup:
>>> + virCgroupFree(&cgroup_vcpu);
>>> + if (cgroup) {
>>> + virCgroupRemove(cgroup);
>>> + virCgroupFree(&cgroup);
>>> + }
>>> +
>>> + return -1;
>>> +}
>>> +
>>>
>>> int qemuRemoveCgroup(struct qemud_driver *driver,
>>> virDomainObjPtr vm,
>>
>
--
Adam Litke
IBM Linux Technology Center
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