[PATCH v2 1/4] numa_conf.c: add helper functions for cpumap operations

[Michal Privoznik]

On 6/10/20 8:35 PM, Daniel Henrique Barboza wrote:
> These helpers will be used in an auto-fill feature for incomplete
> NUMA topologies in the next patch.
> 
> Signed-off-by: Daniel Henrique Barboza <danielhb413 at gmail.com>
> ---
>   src/conf/numa_conf.c     | 46 ++++++++++++++++++++++++++++++++++++++++
>   src/conf/numa_conf.h     |  3 +++
>   src/libvirt_private.syms |  1 +
>   3 files changed, 50 insertions(+)
> 
> diff --git a/src/conf/numa_conf.c b/src/conf/numa_conf.c
> index 09811cb51b..d022685284 100644
> --- a/src/conf/numa_conf.c
> +++ b/src/conf/numa_conf.c
> @@ -1372,3 +1372,49 @@ virDomainNumaGetMemorySize(virDomainNumaPtr numa)
>   
>       return ret;
>   }
> +
> +
> +static int
> +virDomainNumaRemoveCPUsFromMap(virBitmapPtr result, virBitmapPtr exclude)
> +{
> +    size_t i;
> +
> +    for (i = 0; i < virBitmapSize(exclude); i++) {
> +        if (!virBitmapIsBitSet(exclude, i))
> +            continue;
> +
> +        if (virBitmapClearBitExpand(result, i) < 0)
> +            return -1;
> +    }
> +
> +    return 0;
> +}
> +

This exactly what virBitmapSubtract() does :-)

> +
> +int
> +virDomainNumaFillCPUsInNode(virDomainNumaPtr numa, size_t node,
> +                            unsigned int maxCpus)
> +{
> +    g_autoptr(virBitmap) maxCPUsBitmap = virBitmapNew(maxCpus);
> +    size_t i;
> +
> +    if (node >= virDomainNumaGetNodeCount(numa))
> +        return -1;
> +
> +    virBitmapSetAll(maxCPUsBitmap);
> +
> +    for (i = 0; i < numa->nmem_nodes; i++) {
> +        virBitmapPtr nodeCpus = virDomainNumaGetNodeCpumask(numa, i);
> +
> +        if (i == node)
> +            continue;
> +
> +        if (virDomainNumaRemoveCPUsFromMap(maxCPUsBitmap, nodeCpus) < 0)
> +            return -1;
> +    }
> +
> +    virBitmapFree(numa->mem_nodes[node].cpumask);
> +    numa->mem_nodes[node].cpumask = g_steal_pointer(&maxCPUsBitmap);

For some weird reason, I'd feel better if the bitmap is replaced only if 
it differs. I can't really explain why.


Michal