[libvirt] [PATCHv2 4/4] nodeinfo: Get the correct CPU number on AMD Magny Cours platform

[Stefan Berger]

On 05/11/2012 06:41 PM, Eric Blake wrote:
> From: Osier Yang<jyang at redhat.com>
>
> "Instead of developing one CPU with 12 cores, the Magny Cours is
> actually two 6 core “Bulldozer” CPUs combined in to one package"
>
> I.e, each package has two NUMA nodes, and the two numa nodes share
> the same core ID set (0-6), which means parsing the cores number
> from sysfs doesn't work in this case.
>
> And the wrong CPU number could cause three problems for libvirt:
>

[...]

> @@ -265,6 +266,23 @@ int linuxNodeInfoCPUPopulate(FILE *cpuinfo,
>                   &&  (*p == '\0' || *p == '.' || c_isspace(*p)))
>                   nodeinfo->mhz = ui;
>           }
> +
> +        if (STRPREFIX(buf, "cpu cores")) {
> +            char *p;
> +            unsigned int ui;
> +            buf += 9;
> +            while (*buf&&  c_isspace(*buf))
> +                buf++;
> +            if (*buf != ':' || !buf[1]) {
> +                nodeReportError(VIR_ERR_INTERNAL_ERROR,
> +                                "%s", _("parsing cpuinfo cpu MHz"));

Presumably were are parsing the total number of cpu cores ...


> +                return -1;
> +            }
> +            if (virStrToLong_ui(buf+1,&p, 10,&ui) == 0
> +                /* Accept trailing fractional part.  */

... and they don't have fractional parts.

stepping : 1
cpu MHz : 2100.073
cache size : 512 KB
physical id : 0
siblings : 12
core id : 0
cpu cores : 12
apicid : 0
initial apicid : 0

    Stefan