qemu: introduce period/quota tuning for emulator

This patch introduces support of setting emulator's period and
quota to limit cpu bandwidth when the vm starts.  Also updates
XML Schema for new entries and docs.
This commit is contained in:
Hu Tao 2012-08-21 17:18:42 +08:00 committed by Daniel Veillard
parent 1d4395eb47
commit b65dafa812
5 changed files with 69 additions and 3 deletions

View File

@ -388,6 +388,8 @@
<shares>2048</shares>
<period>1000000</period>
<quota>-1</quota>
<emulator_period>1000000</period>
<emulator_quota>-1</quota>
</cputune>
...
</domain>
@ -451,6 +453,28 @@
<span class="since">Only QEMU driver support since 0.9.4, LXC since
0.9.10</span>
</dd>
<dt><code>emulator_period</code></dt>
<dd>
The optional <code>emulator_period</code> element specifies the enforcement
interval(unit: microseconds). Within <code>emulator_period</code>, emulator
threads(those excluding vcpus) of the domain will not be allowed to consume
more than <code>emulator_quota</code> worth of runtime. The value should be
in range [1000, 1000000]. A period with value 0 means no value.
<span class="since">Only QEMU driver support since 0.10.0</span>
</dd>
<dt><code>emulator_quota</code></dt>
<dd>
The optional <code>emulator_quota</code> element specifies the maximum
allowed bandwidth(unit: microseconds) for domain's emulator threads(those
excluding vcpus). A domain with <code>emulator_quota</code> as any negative
value indicates that the domain has infinite bandwidth for emulator threads
(those excluding vcpus), which means that it is not bandwidth controlled.
The value should be in range [1000, 18446744073709551] or less than 0. A
quota with value 0 means no value.
<span class="since">Only QEMU driver support since 0.10.0</span>
</dd>
</dl>

View File

@ -581,6 +581,16 @@
<ref name="cpuquota"/>
</element>
</optional>
<optional>
<element name="emulator_period">
<ref name="cpuperiod"/>
</element>
</optional>
<optional>
<element name="emulator_quota">
<ref name="cpuquota"/>
</element>
</optional>
<zeroOrMore>
<element name="vcpupin">
<attribute name="vcpu">

View File

@ -8344,6 +8344,14 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
&def->cputune.quota) < 0)
def->cputune.quota = 0;
if (virXPathULongLong("string(./cputune/emulator_period[1])", ctxt,
&def->cputune.emulator_period) < 0)
def->cputune.emulator_period = 0;
if (virXPathLongLong("string(./cputune/emulator_quota[1])", ctxt,
&def->cputune.emulator_quota) < 0)
def->cputune.emulator_quota = 0;
if ((n = virXPathNodeSet("./cputune/vcpupin", ctxt, &nodes)) < 0) {
goto error;
}
@ -13102,7 +13110,8 @@ virDomainDefFormatInternal(virDomainDefPtr def,
if (def->cputune.shares || def->cputune.vcpupin ||
def->cputune.period || def->cputune.quota ||
def->cputune.emulatorpin)
def->cputune.emulatorpin ||
def->cputune.emulator_period || def->cputune.emulator_quota)
virBufferAddLit(buf, " <cputune>\n");
if (def->cputune.shares)
@ -13114,6 +13123,17 @@ virDomainDefFormatInternal(virDomainDefPtr def,
if (def->cputune.quota)
virBufferAsprintf(buf, " <quota>%lld</quota>\n",
def->cputune.quota);
if (def->cputune.emulator_period)
virBufferAsprintf(buf, " <emulator_period>%llu"
"</emulator_period>\n",
def->cputune.emulator_period);
if (def->cputune.emulator_quota)
virBufferAsprintf(buf, " <emulator_quota>%lld"
"</emulator_quota>\n",
def->cputune.emulator_quota);
if (def->cputune.vcpupin) {
for (i = 0; i < def->cputune.nvcpupin; i++) {
virBufferAsprintf(buf, " <vcpupin vcpu='%u' ",
@ -13152,7 +13172,8 @@ virDomainDefFormatInternal(virDomainDefPtr def,
if (def->cputune.shares || def->cputune.vcpupin ||
def->cputune.period || def->cputune.quota ||
def->cputune.emulatorpin)
def->cputune.emulatorpin ||
def->cputune.emulator_period || def->cputune.emulator_quota)
virBufferAddLit(buf, " </cputune>\n");
if (def->numatune.memory.nodemask ||

View File

@ -1614,6 +1614,8 @@ struct _virDomainDef {
unsigned long shares;
unsigned long long period;
long long quota;
unsigned long long emulator_period;
long long emulator_quota;
int nvcpupin;
virDomainVcpuPinDefPtr *vcpupin;
virDomainVcpuPinDefPtr emulatorpin;

View File

@ -564,7 +564,7 @@ int qemuSetupCgroupForVcpu(struct qemud_driver *driver, virDomainObjPtr vm)
}
if (priv->nvcpupids == 0 || priv->vcpupids[0] == vm->pid) {
/* If we does not know VCPU<->PID mapping or all vcpus run in the same
/* If we don't know VCPU<->PID mapping or all vcpu runs in the same
* thread, we cannot control each vcpu.
*/
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
@ -631,6 +631,8 @@ int qemuSetupCgroupForEmulator(struct qemud_driver *driver,
virCgroupPtr cgroup = NULL;
virCgroupPtr cgroup_emulator = NULL;
virDomainDefPtr def = vm->def;
unsigned long long period = vm->def->cputune.emulator_period;
long long quota = vm->def->cputune.emulator_quota;
int rc, i;
if (driver->cgroup == NULL)
@ -672,6 +674,13 @@ int qemuSetupCgroupForEmulator(struct qemud_driver *driver,
qemuSetupCgroupEmulatorPin(cgroup_emulator, def->cputune.emulatorpin) < 0)
goto cleanup;
if (period || quota) {
if (qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_CPU)) {
if (qemuSetupCgroupVcpuBW(cgroup_emulator, period, quota) < 0)
goto cleanup;
}
}
virCgroupFree(&cgroup_emulator);
virCgroupFree(&cgroup);
return 0;