Re: [PATCH v3 1/2] perf/bench/numa: Add functions to detect sparse numa nodes

From: Naveen N. Rao
Date: Tue Oct 31 2017 - 11:15:08 EST


Hi Satheesh,

On 2017/08/21 10:15AM, sathnaga@xxxxxxxxxxxxxxxxxx wrote:
> From: Satheesh Rajendran <sathnaga@xxxxxxxxxxxxxxxxxx>
>
> Added functions 1) to get a count of all nodes that are exposed to
> userspace. These nodes could be memoryless cpu nodes or cpuless memory
> nodes, 2) to check given node is present and 3) to check given
> node has cpus
>
> This information can be used to handle sparse/discontiguous nodes.
>
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> Reviewed-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Satheesh Rajendran <sathnaga@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Balamuruhan S <bala24@xxxxxxxxxxxxxxxxxx>
> ---
> tools/perf/bench/numa.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 44 insertions(+)
>
> diff --git a/tools/perf/bench/numa.c b/tools/perf/bench/numa.c
> index 469d65b..2483174 100644
> --- a/tools/perf/bench/numa.c
> +++ b/tools/perf/bench/numa.c
> @@ -215,6 +215,50 @@ static const char * const numa_usage[] = {
> NULL
> };
>
> +/*
> + * To get number of numa nodes present.
> + */
> +static int nr_numa_nodes(void)
> +{
> + int i, nr_nodes = 0;
> +
> + for (i = 0; i < g->p.nr_nodes; i++) {
> + if (numa_bitmask_isbitset(numa_nodes_ptr, i))
> + nr_nodes++;
> + }
> +
> + return nr_nodes;
> +}
> +
> +/*

Please run patches through scripts/checkpatch.pl. There is a trailing
whitespace above...

> + * To check if given numa node is present.
> + */
> +static int is_node_present(int node)
> +{
> + return numa_bitmask_isbitset(numa_nodes_ptr, node);
> +}
> +
> +/*
> + * To check given numa node has cpus.
> + */
> +static bool node_has_cpus(int node)
> +{
> + struct bitmask *cpu = numa_allocate_cpumask();
> + unsigned int i;
> +
> + if (cpu == NULL)
> + return false; /* lets fall back to nocpus safely */
> +
> + if (numa_node_to_cpus(node, cpu) == 0) {

This can be simplified to:
if (cpu && !numa_node_to_cpus(node, cpu)) {

> + for (i = 0; i < cpu->size; i++) {
> + if (numa_bitmask_isbitset(cpu, i))
> + return true;
> + }
> + }

The indentation on those brackets look to be wrong.

> +
> + return false;
> +}
> +

More importantly, you've introduced few functions in this patch, but
none of those are being used. This is not a useful way to split your
patches. In fact, this hurts bisect since trying to build perf with just
this patch applied throws errors.

You seem to be addressing a few different issues related to perf bench
numa. You might want to split your patch based on the specific issue(s)
each change fixes.


- Naveen


> static cpu_set_t bind_to_cpu(int target_cpu)
> {
> cpu_set_t orig_mask, mask;
> --
> 2.7.4
>
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