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set cpu bandwidth for the vm

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The cpu bandwidth is applied at the vcpu group level. We should apply it
at the vm group level too, because the vm may do heavy I/O, and it will affect
the other vm.

We apply cpu bandwidth at the vcpu and the vm group level, so we must ensure
that max(child_quota) <= parent_quota when we modify cpu bandwidth.
This commit is contained in:
Wen Congyang 2011-07-25 13:37:14 +08:00
parent 4d349ef7be
commit 652e55b7a5
2 changed files with 105 additions and 44 deletions
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38
src/qemu/qemu_cgroup.c
View File

@ -435,6 +435,7 @@ int qemuSetupCgroupForVcpu(struct qemud_driver *driver, virDomainObjPtr vm)
unsigned int i;
unsigned long long period = vm->def->cputune.period;
long long quota = vm->def->cputune.quota;
long long vm_quota = 0;
if (driver->cgroup == NULL)
return 0; /* Not supported, so claim success */
@ -447,26 +448,31 @@ int qemuSetupCgroupForVcpu(struct qemud_driver *driver, virDomainObjPtr vm)
goto cleanup;
}
/* Set cpu bandwidth for the vm */
if (period || quota) {
if (qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_CPU)) {
/* Ensure that we can multiply by vcpus without overflowing. */
if (quota > LLONG_MAX / vm->def->vcpus) {
virReportSystemError(EINVAL,
_("%s"),
"Unable to set cpu bandwidth quota");
goto cleanup;
}
if (quota > 0)
vm_quota = quota * vm->def->vcpus;
else
vm_quota = quota;
if (qemuSetupCgroupVcpuBW(cgroup, period, vm_quota) < 0)
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 cannot control each vcpu.
*/
if (period || quota) {
if (qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_CPU)) {
/* Ensure that we can multiply by vcpus without overflowing. */
if (quota > LLONG_MAX / vm->def->vcpus) {
virReportSystemError(EINVAL,
_("%s"),
"Unable to set cpu bandwidth quota");
goto cleanup;
}
if (quota > 0)
quota *= vm->def->vcpus;
if (qemuSetupCgroupVcpuBW(cgroup, period, quota) < 0)
goto cleanup;
}
}
virCgroupFree(&cgroup);
return 0;
}

111
src/qemu/qemu_driver.c
View File

@ -6064,43 +6064,98 @@ qemuSetVcpusBWLive(virDomainObjPtr vm, virCgroupPtr cgroup,
qemuDomainObjPrivatePtr priv = vm->privateData;
virCgroupPtr cgroup_vcpu = NULL;
int rc;
long long vm_quota = 0;
long long old_quota = 0;
unsigned long long old_period = 0;
if (period == 0 && quota == 0)
return 0;
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 cannot control each vcpu.
*/
/* Ensure that we can multiply by vcpus without overflowing. */
if (quota > LLONG_MAX / vm->def->vcpus) {
virReportSystemError(EINVAL,
_("%s"),
"Unable to set cpu bandwidth quota");
goto cleanup;
}
if (quota > 0)
quota *= vm->def->vcpus;
return qemuSetupCgroupVcpuBW(cgroup, period, quota);
/* Ensure that we can multiply by vcpus without overflowing. */
if (quota > LLONG_MAX / vm->def->vcpus) {
virReportSystemError(EINVAL,
_("%s"),
"Unable to set cpu bandwidth quota");
goto cleanup;
}
for (i = 0; i < priv->nvcpupids; i++) {
rc = virCgroupForVcpu(cgroup, i, &cgroup_vcpu, 0);
if (rc < 0) {
virReportSystemError(-rc,
_("Unable to find vcpu cgroup for %s(vcpu:"
" %d)"),
vm->def->name, i);
goto cleanup;
}
if (quota > 0)
vm_quota = quota * vm->def->vcpus;
else
vm_quota = quota;
if (qemuSetupCgroupVcpuBW(cgroup_vcpu, period, quota) < 0)
goto cleanup;
virCgroupFree(&cgroup_vcpu);
rc = virCgroupGetCpuCfsQuota(cgroup, &old_quota);
if (rc < 0) {
virReportSystemError(-rc, "%s",
_("unable to get cpu bandwidth tunable"));
goto cleanup;
}
rc = virCgroupGetCpuCfsPeriod(cgroup, &old_period);
if (rc < 0) {
virReportSystemError(-rc, "%s",
_("unable to get cpu bandwidth period tunable"));
goto cleanup;
}
/*
* If quota will be changed to a small value, we should modify vcpu's quota
* first. Otherwise, we should modify vm's quota first.
*
* If period will be changed to a small value, we should modify vm's period
* first. Otherwise, we should modify vcpu's period first.
*
* If both quota and period will be changed to a big/small value, we cannot
* modify period and quota together.
*/
if ((quota != 0) && (period != 0)) {
if (((quota > old_quota) && (period > old_period)) ||
((quota < old_quota) && (period < old_period))) {
/* modify period */
if (qemuSetVcpusBWLive(vm, cgroup, period, 0) < 0)
goto cleanup;
/* modify quota */
if (qemuSetVcpusBWLive(vm, cgroup, 0, quota) < 0)
goto cleanup;
return 0;
}
}
if (((vm_quota != 0) && (vm_quota > old_quota)) ||
((period != 0) && (period < old_period)))
/* Set cpu bandwidth for the vm */
if (qemuSetupCgroupVcpuBW(cgroup, period, vm_quota) < 0)
goto cleanup;
/* If we does not know VCPU<->PID mapping or all vcpu runs in the same
* thread, we cannot control each vcpu. So we only modify cpu bandwidth
* when each vcpu has a separated thread.
*/
if (priv->nvcpupids != 0 && priv->vcpupids[0] != vm->pid) {
for (i = 0; i < priv->nvcpupids; i++) {
rc = virCgroupForVcpu(cgroup, i, &cgroup_vcpu, 0);
if (rc < 0) {
virReportSystemError(-rc,
_("Unable to find vcpu cgroup for %s(vcpu:"
" %d)"),
vm->def->name, i);
goto cleanup;
}
if (qemuSetupCgroupVcpuBW(cgroup_vcpu, period, quota) < 0)
goto cleanup;
virCgroupFree(&cgroup_vcpu);
}
}
if (((vm_quota != 0) && (vm_quota <= old_quota)) ||
((period != 0) && (period >= old_period)))
/* Set cpu bandwidth for the vm */
if (qemuSetupCgroupVcpuBW(cgroup, period, vm_quota) < 0)
goto cleanup;
return 0;
cleanup: