[libvirt] [PATCHv3 3/4] python: Use virNodeGetCPUMap where possible
Viktor Mihajlovski
mihajlov at linux.vnet.ibm.com
Tue Nov 13 12:54:38 UTC 2012
Modified the places where virNodeGetInfo was used for the purpose
of obtaining the maximum node CPU number. Transparently falling
back to virNodeGetInfo in case of failure.
Wrote a utility function getPyNodeCPUCount for that purpose.
Signed-off-by: Viktor Mihajlovski <mihajlov at linux.vnet.ibm.com>
---
V2 Changes:
Implemented Eric Blake's suggestion to remove code bloat
introduced by first patch version.
New helper function getPyNodeCPUCount is now used to calculate
the number of node CPUs.
python/libvirt-override.c | 87 ++++++++++++++++++++++++++++-------------------
1 file changed, 52 insertions(+), 35 deletions(-)
diff --git a/python/libvirt-override.c b/python/libvirt-override.c
index c07b33a..169df11 100644
--- a/python/libvirt-override.c
+++ b/python/libvirt-override.c
@@ -253,6 +253,39 @@ cleanup:
return NULL;
}
+/*
+ * Utility function to retrieve the number of node CPUs present.
+ * It first tries virGetNodeCPUMap, which will return the
+ * number reliably, if available.
+ * As a fallback and for compatibility with backlevel libvirt
+ * versions virGetNodeInfo will be called to calculate the
+ * CPU number, which has the potential to return a too small
+ * number if some host CPUs are offline.
+ */
+static int
+getPyNodeCPUCount(virConnectPtr conn) {
+ int i_retval;
+ virNodeInfo nodeinfo;
+
+ LIBVIRT_BEGIN_ALLOW_THREADS;
+ i_retval = virNodeGetCPUMap(conn, NULL, NULL, 0);
+ LIBVIRT_END_ALLOW_THREADS;
+
+ if (i_retval < 0) {
+ /* fallback: use nodeinfo */
+ LIBVIRT_BEGIN_ALLOW_THREADS;
+ i_retval = virNodeGetInfo(conn, &nodeinfo);
+ LIBVIRT_END_ALLOW_THREADS;
+ if (i_retval < 0)
+ goto cleanup;
+
+ i_retval = VIR_NODEINFO_MAXCPUS(nodeinfo);
+ }
+
+cleanup:
+ return i_retval;
+}
+
/************************************************************************
* *
* Statistics *
@@ -1338,22 +1371,18 @@ libvirt_virDomainGetVcpus(PyObject *self ATTRIBUTE_UNUSED,
virDomainPtr domain;
PyObject *pyobj_domain, *pyretval = NULL, *pycpuinfo = NULL, *pycpumap = NULL;
PyObject *error = NULL;
- virNodeInfo nodeinfo;
virDomainInfo dominfo;
virVcpuInfoPtr cpuinfo = NULL;
unsigned char *cpumap = NULL;
size_t cpumaplen, i;
- int i_retval;
+ int i_retval, cpunum;
if (!PyArg_ParseTuple(args, (char *)"O:virDomainGetVcpus",
&pyobj_domain))
return NULL;
domain = (virDomainPtr) PyvirDomain_Get(pyobj_domain);
- LIBVIRT_BEGIN_ALLOW_THREADS;
- i_retval = virNodeGetInfo(virDomainGetConnect(domain), &nodeinfo);
- LIBVIRT_END_ALLOW_THREADS;
- if (i_retval < 0)
+ if ((cpunum = getPyNodeCPUCount(virDomainGetConnect(domain))) < 0)
return VIR_PY_INT_FAIL;
LIBVIRT_BEGIN_ALLOW_THREADS;
@@ -1365,7 +1394,7 @@ libvirt_virDomainGetVcpus(PyObject *self ATTRIBUTE_UNUSED,
if (VIR_ALLOC_N(cpuinfo, dominfo.nrVirtCpu) < 0)
return PyErr_NoMemory();
- cpumaplen = VIR_CPU_MAPLEN(VIR_NODEINFO_MAXCPUS(nodeinfo));
+ cpumaplen = VIR_CPU_MAPLEN(cpunum);
if (xalloc_oversized(dominfo.nrVirtCpu, cpumaplen) ||
VIR_ALLOC_N(cpumap, dominfo.nrVirtCpu * cpumaplen) < 0) {
error = PyErr_NoMemory();
@@ -1423,11 +1452,11 @@ libvirt_virDomainGetVcpus(PyObject *self ATTRIBUTE_UNUSED,
goto cleanup;
}
for (i = 0 ; i < dominfo.nrVirtCpu ; i++) {
- PyObject *info = PyTuple_New(VIR_NODEINFO_MAXCPUS(nodeinfo));
+ PyObject *info = PyTuple_New(cpunum);
int j;
if (info == NULL)
goto cleanup;
- for (j = 0 ; j < VIR_NODEINFO_MAXCPUS(nodeinfo) ; j++) {
+ for (j = 0 ; j < cpunum ; j++) {
PyObject *item = NULL;
if ((item = PyBool_FromLong(VIR_CPU_USABLE(cpumap, cpumaplen, i, j))) == NULL ||
PyTuple_SetItem(info, j, item) < 0) {
@@ -1467,9 +1496,8 @@ libvirt_virDomainPinVcpu(PyObject *self ATTRIBUTE_UNUSED,
virDomainPtr domain;
PyObject *pyobj_domain, *pycpumap;
PyObject *ret = NULL;
- virNodeInfo nodeinfo;
unsigned char *cpumap;
- int cpumaplen, i, vcpu, tuple_size;
+ int cpumaplen, i, vcpu, tuple_size, cpunum;
int i_retval;
if (!PyArg_ParseTuple(args, (char *)"OiO:virDomainPinVcpu",
@@ -1477,10 +1505,7 @@ libvirt_virDomainPinVcpu(PyObject *self ATTRIBUTE_UNUSED,
return NULL;
domain = (virDomainPtr) PyvirDomain_Get(pyobj_domain);
- LIBVIRT_BEGIN_ALLOW_THREADS;
- i_retval = virNodeGetInfo(virDomainGetConnect(domain), &nodeinfo);
- LIBVIRT_END_ALLOW_THREADS;
- if (i_retval < 0)
+ if ((cpunum = getPyNodeCPUCount(virDomainGetConnect(domain))) < 0)
return VIR_PY_INT_FAIL;
if (PyTuple_Check(pycpumap)) {
@@ -1492,7 +1517,7 @@ libvirt_virDomainPinVcpu(PyObject *self ATTRIBUTE_UNUSED,
return ret;
}
- cpumaplen = VIR_CPU_MAPLEN(VIR_NODEINFO_MAXCPUS(nodeinfo));
+ cpumaplen = VIR_CPU_MAPLEN(cpunum);
if (VIR_ALLOC_N(cpumap, cpumaplen) < 0)
return PyErr_NoMemory();
@@ -1509,7 +1534,7 @@ libvirt_virDomainPinVcpu(PyObject *self ATTRIBUTE_UNUSED,
VIR_UNUSE_CPU(cpumap, i);
}
- for (; i < VIR_NODEINFO_MAXCPUS(nodeinfo); i++)
+ for (; i < cpunum; i++)
VIR_UNUSE_CPU(cpumap, i);
LIBVIRT_BEGIN_ALLOW_THREADS;
@@ -1534,9 +1559,8 @@ libvirt_virDomainPinVcpuFlags(PyObject *self ATTRIBUTE_UNUSED,
virDomainPtr domain;
PyObject *pyobj_domain, *pycpumap;
PyObject *ret = NULL;
- virNodeInfo nodeinfo;
unsigned char *cpumap;
- int cpumaplen, i, vcpu, tuple_size;
+ int cpumaplen, i, vcpu, tuple_size, cpunum;
unsigned int flags;
int i_retval;
@@ -1545,10 +1569,7 @@ libvirt_virDomainPinVcpuFlags(PyObject *self ATTRIBUTE_UNUSED,
return NULL;
domain = (virDomainPtr) PyvirDomain_Get(pyobj_domain);
- LIBVIRT_BEGIN_ALLOW_THREADS;
- i_retval = virNodeGetInfo(virDomainGetConnect(domain), &nodeinfo);
- LIBVIRT_END_ALLOW_THREADS;
- if (i_retval < 0)
+ if ((cpunum = getPyNodeCPUCount(virDomainGetConnect(domain))) < 0)
return VIR_PY_INT_FAIL;
if (PyTuple_Check(pycpumap)) {
@@ -1560,7 +1581,7 @@ libvirt_virDomainPinVcpuFlags(PyObject *self ATTRIBUTE_UNUSED,
return ret;
}
- cpumaplen = VIR_CPU_MAPLEN(VIR_NODEINFO_MAXCPUS(nodeinfo));
+ cpumaplen = VIR_CPU_MAPLEN(cpunum);
if (VIR_ALLOC_N(cpumap, cpumaplen) < 0)
return PyErr_NoMemory();
@@ -1577,7 +1598,7 @@ libvirt_virDomainPinVcpuFlags(PyObject *self ATTRIBUTE_UNUSED,
VIR_UNUSE_CPU(cpumap, i);
}
- for (; i < VIR_NODEINFO_MAXCPUS(nodeinfo); i++)
+ for (; i < cpunum; i++)
VIR_UNUSE_CPU(cpumap, i);
LIBVIRT_BEGIN_ALLOW_THREADS;
@@ -1599,23 +1620,19 @@ libvirt_virDomainGetVcpuPinInfo(PyObject *self ATTRIBUTE_UNUSED,
PyObject *args) {
virDomainPtr domain;
PyObject *pyobj_domain, *pycpumaps = NULL;
- virNodeInfo nodeinfo;
virDomainInfo dominfo;
unsigned char *cpumaps;
size_t cpumaplen, vcpu, pcpu;
unsigned int flags;
- int i_retval;
+ int i_retval, cpunum;
if (!PyArg_ParseTuple(args, (char *)"Oi:virDomainGetVcpuPinInfo",
&pyobj_domain, &flags))
return NULL;
domain = (virDomainPtr) PyvirDomain_Get(pyobj_domain);
- LIBVIRT_BEGIN_ALLOW_THREADS;
- i_retval = virNodeGetInfo(virDomainGetConnect(domain), &nodeinfo);
- LIBVIRT_END_ALLOW_THREADS;
- if (i_retval < 0)
- return VIR_PY_NONE;
+ if ((cpunum = getPyNodeCPUCount(virDomainGetConnect(domain))) < 0)
+ return VIR_PY_INT_FAIL;
LIBVIRT_BEGIN_ALLOW_THREADS;
i_retval = virDomainGetInfo(domain, &dominfo);
@@ -1623,7 +1640,7 @@ libvirt_virDomainGetVcpuPinInfo(PyObject *self ATTRIBUTE_UNUSED,
if (i_retval < 0)
return VIR_PY_NONE;
- cpumaplen = VIR_CPU_MAPLEN(VIR_NODEINFO_MAXCPUS(nodeinfo));
+ cpumaplen = VIR_CPU_MAPLEN(cpunum);
if (xalloc_oversized(dominfo.nrVirtCpu, cpumaplen) ||
VIR_ALLOC_N(cpumaps, dominfo.nrVirtCpu * cpumaplen) < 0)
goto cleanup;
@@ -1639,11 +1656,11 @@ libvirt_virDomainGetVcpuPinInfo(PyObject *self ATTRIBUTE_UNUSED,
goto cleanup;
for (vcpu = 0; vcpu < dominfo.nrVirtCpu; vcpu++) {
- PyObject *mapinfo = PyTuple_New(VIR_NODEINFO_MAXCPUS(nodeinfo));
+ PyObject *mapinfo = PyTuple_New(cpunum);
if (mapinfo == NULL)
goto cleanup;
- for (pcpu = 0; pcpu < VIR_NODEINFO_MAXCPUS(nodeinfo); pcpu++) {
+ for (pcpu = 0; pcpu < cpunum; pcpu++) {
PyTuple_SetItem(mapinfo, pcpu,
PyBool_FromLong(VIR_CPU_USABLE(cpumaps, cpumaplen, vcpu, pcpu)));
}
--
1.7.12.4
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