Re: [PATCH v2 1/4] numa_conf.c: add helper functions for cpumap operations
On 6/18/20 7:34 AM, Michal Privoznik wrote:
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(a)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 :-)
Completely forgot about virBitmapSubtract() after I tried to use it
in an earlier interaction of the code and it didn't suit what I
need. Granted, I was doing it a convoluted way of doing what I'm
doing now. virBitmapSubtract really works as a replacement in the
code below.
> +
> +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.
I think it's ok to check for virBitmapEqual() before replacing the
existing one.
DHB
Michal