Re: [Libvirt-cim] [PATCH] Add dynamic VCPU adjustments
Dan Smith wrote:
# HG changeset patch
# User Dan Smith <danms(a)us.ibm.com>
# Date 1201029734 28800
# Node ID 84f80a8040eb29109d0fce50b582582527c2e50e
# Parent 47438edf32be70e65bdb814ab609a70304fad2f4
Add dynamic VCPU adjustments
Signed-off-by: Dan Smith <danms(a)us.ibm.com>
diff -r 47438edf32be -r 84f80a8040eb libxkutil/device_parsing.c
--- a/libxkutil/device_parsing.c Tue Jan 22 10:55:59 2008 -0800
+++ b/libxkutil/device_parsing.c Tue Jan 22 11:22:14 2008 -0800
@@ -897,11 +897,38 @@ static int change_memory(virDomainPtr do
return 1;
}
+static int change_vcpus(virDomainPtr dom, int delta)
+{
+ int count = 32;
+ int max;
+ virVcpuInfoPtr foo;
+
+ /* This is retarded, but I don't think there's an API to
+ * expose the total VCPU number otherwise
+ */
I saw that virDomainInfo contains a field nrVirtCpu. Maybe this is an
alternative.
+ for (max = count; max == count; max += 32) {
+ foo = calloc(max, sizeof(*foo));
+ count = virDomainGetVcpus(dom, foo, max, NULL, 0);
Wouldn't the case "virDomainGetVcpus = 32" cause an endless loop ?
On
the other hand ... I can not quite follow the reason of this for loop,
which exits right after the first run in case of "count < 32" ?
+ free(foo);
+ }
+
+ CU_DEBUG("Changing VCPUs of %s from %i to %i",
+ virDomainGetName(dom),
+ count,
+ count + delta);
+
+ virDomainSetVcpus(dom, count + delta);
This function returns -1 in case of failure. Shouldn't this error case
be reported to the caller ? With the current setup the caller expects
that everything worked.
+
+ return 1;
+}
+
int attach_device(virDomainPtr dom, struct virt_device *dev)
{
if ((dev->type == VIRT_DEV_NET) ||
(dev->type == VIRT_DEV_DISK))
return _change_device(dom, dev, true);
+ else if (dev->type == VIRT_DEV_VCPU)
+ return change_vcpus(dom, 1);
CU_DEBUG("Unhandled device type %i", dev->type);
@@ -913,6 +940,8 @@ int detach_device(virDomainPtr dom, stru
if ((dev->type == VIRT_DEV_NET) ||
(dev->type == VIRT_DEV_DISK))
return _change_device(dom, dev, false);
+ else if (dev->type == VIRT_DEV_VCPU)
+ return change_vcpus(dom, -1);
CU_DEBUG("Unhandled device type %i", dev->type);
--
Regards
Heidi Eckhart
Software Engineer
IBM Linux Technology Center - Open Hypervisor