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qemu: cgroup: Properly set up vcpu pinning

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When the default cpuset or automatic numa placement is used libvirt
would place the whole parent cgroup in the specified cpuset. This then
disallowed to re-pin the vcpus to a different cpu.

This patch pins only the vcpu threads to the default cpuset and thus
allows to re-pin them later.

The following config would fail to start:
<domain type='kvm'>
  ...
  <vcpu placement='static' cpuset='0-1' current='2'>4</vcpu>
  <cputune>
    <vcpupin vcpu='0' cpuset='2-3'/>
    ...

This is a regression since a39f69d2b.
This commit is contained in:
Peter Krempa 2015-03-27 10:23:19 +01:00
parent 7095006921
commit f0fa9080d4
1 changed files with 20 additions and 33 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

53
src/qemu/qemu_cgroup.c
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@ -645,8 +645,6 @@ static int
qemuSetupCpusetCgroup(virDomainObjPtr vm)
{
qemuDomainObjPrivatePtr priv = vm->privateData;
char *cpu_mask = NULL;
int ret = -1;
if (!virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_CPUSET))
return 0;
@ -654,25 +652,7 @@ qemuSetupCpusetCgroup(virDomainObjPtr vm)
if (virCgroupSetCpusetMemoryMigrate(priv->cgroup, true) < 0)
return -1;
if (vm->def->cpumask ||
(vm->def->placement_mode == VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO)) {
if (vm->def->placement_mode == VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO)
cpu_mask = virBitmapFormat(priv->autoCpuset);
else
cpu_mask = virBitmapFormat(vm->def->cpumask);
if (!cpu_mask)
goto cleanup;
if (virCgroupSetCpusetCpus(priv->cgroup, cpu_mask) < 0)
goto cleanup;
}
ret = 0;
cleanup:
VIR_FREE(cpu_mask);
return ret;
return 0;
}
@ -1079,20 +1059,27 @@ qemuSetupCgroupForVcpu(virDomainObjPtr vm)
/* Set vcpupin in cgroup if vcpupin xml is provided */
if (virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_CPUSET)) {
/* find the right CPU to pin, otherwise
* qemuSetupCgroupVcpuPin will fail. */
virBitmapPtr cpumap = NULL;
/* try to use the default cpu maps */
if (vm->def->placement_mode == VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO)
cpumap = priv->autoCpuset;
else
cpumap = vm->def->cpumask;
/* lookup a more specific pinning info */
for (j = 0; j < def->cputune.nvcpupin; j++) {
if (def->cputune.vcpupin[j]->id != i)
continue;
if (qemuSetupCgroupVcpuPin(cgroup_vcpu,
def->cputune.vcpupin,
def->cputune.nvcpupin,
i) < 0)
goto cleanup;
break;
if (def->cputune.vcpupin[j]->id == i) {
cpumap = def->cputune.vcpupin[j]->cpumask;
break;
}
}
if (!cpumap)
continue;
if (qemuSetupCgroupEmulatorPin(cgroup_vcpu, cpumap) < 0)
goto cleanup;
}
virCgroupFree(&cgroup_vcpu);