Re: [libvirt] [PATCH 3/7] conf: Initialize the pinning policy for vcpus

Document for <vcpu>'s "cpuset" says: Since 0.4.4, this element can contain an optional cpuset attribute, which is a comma-separated list of physical CPU numbers that virtual CPUs can be pinned to. However, it's not the truth, libvirt actually pins the domain process to the specified pCPUs by "cpuset" of <vcpu>. And the vcpu thread are pinned to all available pCPUs if no <vcpupin> is specified for it. PATCH 1/7 provides more details on how this set resolve the confused relationship between <vcpu> and <vcpupin>. This patch is to implement the codes to inherit <vcpu>'s "cpuset" for vcpu that doesn't have <vcpupin> specified, and <vcpupin> for these vcpu will be ignored when formating. Underlying driver implementation will make sure the vcpu thread pinned to correct pCPUs. --- src/conf/domain_conf.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 70 insertions(+), 1 deletions(-) diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index d8ea8ce..e404a68 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -8810,6 +8810,41 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps, } VIR_FREE(nodes); + /* Initialize the pinning policy for vcpus which doesn't has + * the policy specified explicitly as def->cpuset. + */ + if (def->cpumask) { + if (!def->cputune.vcpupin) { + if (VIR_ALLOC_N(def->cputune.vcpupin, def->vcpus) < 0) { + virReportOOMError(); + goto error; + } + } else { + if (VIR_REALLOC_N(def->cputune.vcpupin, def->vcpus) < 0) { + virReportOOMError(); + goto error; + } + }

+ + for (i = 0; i < def->vcpus; i++) { + if (!virDomainVcpuPinIsDuplicate(def->cputune.vcpupin, + def->cputune.nvcpupin, + i)) { + virDomainVcpuPinDefPtr vcpupin = NULL; + + if (VIR_ALLOC(vcpupin) < 0) { + virReportOOMError(); + goto error; + } + + vcpupin->cpumask = virBitmapNew(VIR_DOMAIN_CPUMASK_LEN); + virBitmapCopy(vcpupin->cpumask, def->cpumask); + vcpupin->vcpuid = i; + def->cputune.vcpupin[def->cputune.nvcpupin++] = vcpupin; + } + } + } + if ((n = virXPathNodeSet("./cputune/emulatorpin", ctxt, &nodes)) < 0) { virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("cannot extract emulatorpin nodes"));