[libvirt] [PATCH 5/6] qemu: Implement hypervisor's period and quota tunable XML configuration and parsing
Hu Tao
hutao at cn.fujitsu.com
Thu May 17 03:13:56 UTC 2012
On Wed, Apr 25, 2012 at 05:46:06PM +0800, Wen Congyang wrote:
> set hypervisor's period and quota when the vm starts. It will affect to set
> vm's period and quota: donot set vm's period and quota if we limit hypevisor
> thread's bandwidth(hypervisor_quota > 0).
> ---
> src/conf/domain_conf.c | 25 ++++++++++++++-
> src/conf/domain_conf.h | 2 +
> src/qemu/qemu_cgroup.c | 37 ++++++++++++++++-------
> src/qemu/qemu_driver.c | 75 ++++++++++++++++++++++++++++++------------------
> 4 files changed, 98 insertions(+), 41 deletions(-)
>
> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
> index 5ab052a..28a6436 100644
> --- a/src/conf/domain_conf.c
> +++ b/src/conf/domain_conf.c
> @@ -7931,6 +7931,14 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
> &def->cputune.quota) < 0)
> def->cputune.quota = 0;
>
> + if (virXPathULongLong("string(./cputune/hypervisor_period[1])", ctxt,
> + &def->cputune.hypervisor_period) < 0)
> + def->cputune.hypervisor_period = 0;
> +
> + if (virXPathLongLong("string(./cputune/hypervisor_quota[1])", ctxt,
> + &def->cputune.hypervisor_quota) < 0)
> + def->cputune.hypervisor_quota = 0;
> +
> if ((n = virXPathNodeSet("./cputune/vcpupin", ctxt, &nodes)) < 0) {
> goto error;
> }
> @@ -12406,7 +12414,8 @@ virDomainDefFormatInternal(virDomainDefPtr def,
> virBufferAsprintf(buf, ">%u</vcpu>\n", def->maxvcpus);
>
> if (def->cputune.shares || def->cputune.vcpupin ||
> - def->cputune.period || def->cputune.quota)
> + def->cputune.period || def->cputune.quota ||
> + def->cputune.hypervisor_period || def->cputune.hypervisor_quota)
> virBufferAddLit(buf, " <cputune>\n");
>
> if (def->cputune.shares)
> @@ -12418,6 +12427,17 @@ virDomainDefFormatInternal(virDomainDefPtr def,
> if (def->cputune.quota)
> virBufferAsprintf(buf, " <quota>%lld</quota>\n",
> def->cputune.quota);
> +
> + if (def->cputune.hypervisor_period)
> + virBufferAsprintf(buf, " <hypervisor_period>%llu"
> + "</hypervisor_period>\n",
> + def->cputune.hypervisor_period);
> +
> + if (def->cputune.hypervisor_period)
> + virBufferAsprintf(buf, " <hypervisor_quota>%lld"
> + "</hypervisor_quota>\n",
> + def->cputune.hypervisor_quota);
> +
> if (def->cputune.vcpupin) {
> for (i = 0; i < def->cputune.nvcpupin; i++) {
> virBufferAsprintf(buf, " <vcpupin vcpu='%u' ",
> @@ -12439,7 +12459,8 @@ virDomainDefFormatInternal(virDomainDefPtr def,
> }
>
> if (def->cputune.shares || def->cputune.vcpupin ||
> - def->cputune.period || def->cputune.quota)
> + def->cputune.period || def->cputune.quota ||
> + def->cputune.hypervisor_period || def->cputune.hypervisor_quota)
> virBufferAddLit(buf, " </cputune>\n");
>
> if (def->numatune.memory.nodemask) {
> diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
> index 0eed60e..2a37e26 100644
> --- a/src/conf/domain_conf.h
> +++ b/src/conf/domain_conf.h
> @@ -1558,6 +1558,8 @@ struct _virDomainDef {
> unsigned long shares;
> unsigned long long period;
> long long quota;
> + unsigned long long hypervisor_period;
> + long long hypervisor_quota;
> int nvcpupin;
> virDomainVcpuPinDefPtr *vcpupin;
> } cputune;
> diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c
> index 727c0d4..7c6ef33 100644
> --- a/src/qemu/qemu_cgroup.c
> +++ b/src/qemu/qemu_cgroup.c
> @@ -493,17 +493,23 @@ int qemuSetupCgroupForVcpu(struct qemud_driver *driver, virDomainObjPtr vm)
> goto cleanup;
> }
Check if cgroup CPU is active here:
if (!qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_CPU)) {
virReportSystemError(EINVAL,
_("%s"),
"Cgroup CPU is not active.");
goto cleanup;
}
and remove all following checks in this function.
>
> - /* 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;
> - }
> + /*
> + * Set cpu bandwidth for the vm if any of the following is true:
> + * 1. we donot know VCPU<->PID mapping or all vcpus run in the same thread
> + * 2. the hypervisor threads are not limited(quota <= 0)
> + */
> + if ((period || quota) &&
> + 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 (priv->nvcpupids == 0 || priv->vcpupids[0] == vm->pid ||
> + vm->def->cputune.hypervisor_quota <= 0) {
> if (quota > 0)
> vm_quota = quota * vm->def->vcpus;
> else
> @@ -514,7 +520,7 @@ 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 vcpu runs in the same
> + /* If we donot know VCPU<->PID mapping or all vcpus run in the same
> * thread, we cannot control each vcpu.
> */
> virCgroupFree(&cgroup);
> @@ -570,6 +576,8 @@ int qemuSetupCgroupForHypervisor(struct qemud_driver *driver,
> virCgroupPtr cgroup = NULL;
> virCgroupPtr cgroup_hypervisor = NULL;
> qemuDomainObjPrivatePtr priv = vm->privateData;
> + unsigned long long period = vm->def->cputune.hypervisor_period;
> + long long quota = vm->def->cputune.hypervisor_quota;
> int rc;
>
> if (driver->cgroup == NULL)
> @@ -608,6 +616,13 @@ int qemuSetupCgroupForHypervisor(struct qemud_driver *driver,
> goto cleanup;
> }
>
> + if (period || quota) {
> + if (qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_CPU)) {
> + if (qemuSetupCgroupVcpuBW(cgroup_hypervisor, period, quota) < 0)
Actually, qemuSetupCgroupVcpuBW just changes the cgroup's
settings(period, quota), it doesn't care about what the
cgroup is associated with. So can we change the name to
qemuSetupCgroupBW?
> + goto cleanup;
> + }
> + }
> +
> virCgroupFree(&cgroup_hypervisor);
> virCgroupFree(&cgroup);
> return 0;
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index c3555ca..2e40aee 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -7007,6 +7007,7 @@ qemuSetVcpusBWLive(virDomainObjPtr vm, virCgroupPtr cgroup,
> int rc;
> long long vm_quota = 0;
> long long old_quota = 0;
> + long long hypervisor_quota = vm->def->cputune.hypervisor_quota;
> unsigned long long old_period = 0;
>
> if (period == 0 && quota == 0)
> @@ -7039,6 +7040,16 @@ qemuSetVcpusBWLive(virDomainObjPtr vm, virCgroupPtr cgroup,
> goto cleanup;
> }
>
> + /* If we donot know VCPU<->PID mapping or all vcpu runs in the same
> + * thread, we cannot control each vcpu. So we only modify cpu bandwidth
> + * for the vm.
> + */
> + if (priv->nvcpupids == 0 || priv->vcpupids[0] == vm->pid) {
> + if (qemuSetupCgroupVcpuBW(cgroup, period, vm_quota) < 0)
> + goto cleanup;
> + return 0;
> + }
> +
> /*
> * If quota will be changed to a small value, we should modify vcpu's quota
> * first. Otherwise, we should modify vm's quota first.
> @@ -7048,8 +7059,12 @@ qemuSetVcpusBWLive(virDomainObjPtr vm, virCgroupPtr cgroup,
> *
> * If both quota and period will be changed to a big/small value, we cannot
> * modify period and quota together.
> + *
> + * If the hypervisor threads are limited, we can update period for vm first,
> + * and then we can modify period and quota for the vcpu together even if
> + * they will be changed to a big/small value.
> */
> - if ((quota != 0) && (period != 0)) {
> + if (hypervisor_quota <= 0 && quota != 0 && period != 0) {
> if (((quota > old_quota) && (period > old_period)) ||
> ((quota < old_quota) && (period < old_period))) {
> /* modify period */
> @@ -7063,40 +7078,44 @@ qemuSetVcpusBWLive(virDomainObjPtr vm, virCgroupPtr cgroup,
> }
> }
>
> - 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 the hypervisor threads are not limited, set cpu bandwidth for the
> + * vm.
> */
> - 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)
> + if (vm->def->cputune.hypervisor_quota <= 0) {
> + if (((vm_quota != 0) && (vm_quota > old_quota)) ||
> + ((period != 0) && (period < old_period)))
> + if (qemuSetupCgroupVcpuBW(cgroup, period, vm_quota) < 0)
> goto cleanup;
> + }
>
> - virCgroupFree(&cgroup_vcpu);
> + /* each vcpu has a separated thread, so we modify cpu bandwidth for vcpu. */
> + 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 (((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)
> + if (qemuSetupCgroupVcpuBW(cgroup_vcpu, period, quota) < 0)
> goto cleanup;
>
> + virCgroupFree(&cgroup_vcpu);
> + }
> +
> + /*
> + * If the hypervisor threads are not limited, set cpu bandwidth for the vm.
> + */
This makes me confused. Why do we have to limit the whole vm when the
hypervisor threads are not limited? Users may want to limit the vcpus
only.
We have 3 situations now:
1. limit the vcpus only.
2. limit the hypervisor but not vcpus.
3. limit the whole vm.
I'm not thinking this patch is capable with all of these 3 situations.
> + if (hypervisor_quota <= 0) {
> + if (((vm_quota != 0) && (vm_quota <= old_quota)) ||
> + ((period != 0) && (period >= old_period)))
> + if (qemuSetupCgroupVcpuBW(cgroup, period, vm_quota) < 0)
> + goto cleanup;
> + }
> +
> return 0;
>
> cleanup:
> --
> 1.7.1
>
> --
> libvir-list mailing list
> libvir-list at redhat.com
> https://www.redhat.com/mailman/listinfo/libvir-list
--
Thanks,
Hu Tao
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