Re: [PATCH v5 03/14] hw/core/machine: Wrap target specific parameters together

[Philippe Mathieu-Daudé]

On 12/28/21 10:22, Yanan Wang wrote:
> Wrap the CPU target specific parameters together into a single
> variable except generic sockets/cores/threads, to make related
> code lines shorter and more concise.
> 
> No functional change intended.
> 
> Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
> ---
>  hw/core/machine-smp.c | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/hw/core/machine-smp.c b/hw/core/machine-smp.c
> index b39ed21e65..4547d7bbdc 100644
> --- a/hw/core/machine-smp.c
> +++ b/hw/core/machine-smp.c
> @@ -79,6 +79,7 @@ void machine_parse_smp_config(MachineState *ms,
>      unsigned cores   = config->has_cores ? config->cores : 0;
>      unsigned threads = config->has_threads ? config->threads : 0;
>      unsigned maxcpus = config->has_maxcpus ? config->maxcpus : 0;
> +    unsigned others;
>  
>      /*
>       * Specified CPU topology parameters must be greater than zero,
> @@ -111,6 +112,8 @@ void machine_parse_smp_config(MachineState *ms,
>      dies = dies > 0 ? dies : 1;
>      clusters = clusters > 0 ? clusters : 1;
>  
> +    others = dies * clusters;

This doesn't seem clearer to me...

>      /* compute missing values based on the provided ones */
>      if (cpus == 0 && maxcpus == 0) {
>          sockets = sockets > 0 ? sockets : 1;
> @@ -124,30 +127,30 @@ void machine_parse_smp_config(MachineState *ms,
>              if (sockets == 0) {
>                  cores = cores > 0 ? cores : 1;
>                  threads = threads > 0 ? threads : 1;
> -                sockets = maxcpus / (dies * clusters * cores * threads);
> +                sockets = maxcpus / (cores * threads * others);
>              } else if (cores == 0) {
>                  threads = threads > 0 ? threads : 1;
> -                cores = maxcpus / (sockets * dies * clusters * threads);
> +                cores = maxcpus / (sockets * threads * others);
>              }
>          } else {
>              /* prefer cores over sockets since 6.2 */
>              if (cores == 0) {
>                  sockets = sockets > 0 ? sockets : 1;
>                  threads = threads > 0 ? threads : 1;
> -                cores = maxcpus / (sockets * dies * clusters * threads);
> +                cores = maxcpus / (sockets * threads * others);
>              } else if (sockets == 0) {
>                  threads = threads > 0 ? threads : 1;
> -                sockets = maxcpus / (dies * clusters * cores * threads);
> +                sockets = maxcpus / (cores * threads * others);
>              }
>          }
>  
>          /* try to calculate omitted threads at last */
>          if (threads == 0) {
> -            threads = maxcpus / (sockets * dies * clusters * cores);
> +            threads = maxcpus / (sockets * cores * others);
>          }
>      }
>  
> -    maxcpus = maxcpus > 0 ? maxcpus : sockets * dies * clusters * cores * 
> threads;
> +    maxcpus = maxcpus > 0 ? maxcpus : sockets * cores * threads * others;
>      cpus = cpus > 0 ? cpus : maxcpus;
>  
>      ms->smp.cpus = cpus;
> @@ -159,7 +162,7 @@ void machine_parse_smp_config(MachineState *ms,
>      ms->smp.max_cpus = maxcpus;
>  
>      /* sanity-check of the computed topology */
> -    if (sockets * dies * clusters * cores * threads != maxcpus) {
> +    if (sockets * cores * threads * others != maxcpus) {
>          g_autofree char *topo_msg = cpu_hierarchy_to_string(ms);
>          error_setg(errp, "Invalid CPU topology: "
>                     "product of the hierarchy must match maxcpus: "