>Hi Yongkang,
>
>>Hi all,
>>
>>I find a strange issue that if I only assign 1 or 2 vcpus to dom0, I can
>>not use vcpu-pin to pin the No. 0 vcpu. It will report: "Invalid
argument".
>> But it works, if I let Xen0 see all vcpus when booting.
>>
>>For example, in IA32, set (dom0-cpus 1)
>>After Xen0 boot up, "xm vcpu-p 0 0 0" will see errors.
>>If setting (dom0-cpus 0), above command works.
>>
>>In IA64, set dom0_max_vcpus=2 (totally have 16 vcpus)
>>After Xen0 boot up, "xm vcpu-p 0 0 0" will see errors.
>>But "xm vcpu-p 0 1 0" works.
>>
>
>I think that you can solve this problem by applying the following
>patch, and inputting "xm vcpu-pin 0 0 0" from two consoles at the
>same time... Need many retry :-)
>
Hi Yongkang,
Sorry, that is an expected behavior, my patch is far from perfect.
As Keir noted, we need a scheduler fix to correctly solve this.
Not apply my patch:
+---------------+------------------------------+-----------+
| Target domain | pCPU that vCPU processing | Result |
| | ''xm vcpu-pin'' command works | |
+---------------+------------------------------+-----------+
| Domain-0 | == Target pCPU | Error(22) |
| +------------------------------+-----------+
| | != Target pCPU | Error(22) |
+---------------+------------------------------+-----------+
| Domain-U | - | OK |
+---------------+------------------------------+-----------+
Apply my patch:
+---------------+------------------------------+-----------+
| Target domain | pCPU that vCPU processing | Result |
| | ''xm vcpu-pin'' command works | |
+---------------+------------------------------+-----------+
| Domain-0 | == Target pCPU | OK |
| +------------------------------+-----------+
| | != Target pCPU | Error(16) |
+---------------+------------------------------+-----------+
| Domain-U | - | OK |
+---------------+------------------------------+-----------+
Best regards,
Kan
>diff -r 5b9ff5e8653a xen/common/domctl.c
>--- a/xen/common/domctl.c Sun Aug 27 06:56:01 2006 +0100
>+++ b/xen/common/domctl.c Mon Aug 28 18:01:28 2006 +0900
>@@ -380,13 +380,6 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domc
>
> if ( op->cmd == XEN_DOMCTL_setvcpuaffinity )
> {
>- if ( v == current )
>- {
>- ret = -EINVAL;
>- put_domain(d);
>- break;
>- }
>-
> xenctl_cpumap_to_cpumask(
> &new_affinity, &op->u.vcpuaffinity.cpumap);
> ret = vcpu_set_affinity(v, &new_affinity);
>
>
>But, if Domain-0 has one virtual CPU, this problem cannot be solved
>even if applying this patch. If you are using CREDIT scheduler,
>''xm vcpu-pin 0 0 0'' makes an error by the following line.
>
>
>static int
>csched_vcpu_set_affinity(struct vcpu *vc, cpumask_t *affinity)
>{
> unsigned long flags;
> int lcpu;
>
> if ( vc == current )
> {
> /* No locking needed but also can''t move on the spot... */
> if ( !cpu_isset(vc->processor, *affinity) )
> return -EBUSY; <---- This!
>
> vc->cpu_affinity = *affinity;
> }
>
>
>Hi Keir,
>Do you have good ideas to solve this problem?
>
>
>Best regards,
> Kan
>
>>Best Regards,
>>Yongkang (Kangkang)
>>
>>_______________________________________________
>>Xen-ia64-devel mailing list
>>Xen-ia64-devel@lists.xensource.com
>>http://lists.xensource.com/xen-ia64-devel
>
>
>
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