Re: [Patch v2 5/5] perf c2c: Rename "Region" column to "Range" for consistency

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Low] perf c2c: Range column header conflates region IDs with MRRM
  range indices
--

commit 359275a3e2aec93ecd4fbf0366bae0325d3a6862
Author: Dapeng Mi <dapeng1.mi@linux.intel.com>

perf c2c: Rename "Region" column to "Range" for consistency

This commit renames the header of dim_dcacheline_mem_region and
dim_offset_mem_region from "Region" to "Range" and reduces their column
width from 6 to 5.

> diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c
> index a2dcc65d6b3ce..94fca3e4fc0a0 100644
> --- a/tools/perf/builtin-c2c.c
> +++ b/tools/perf/builtin-c2c.c
> @@ -1395,11 +1395,11 @@ static struct c2c_dimension dim_dcacheline_node = {
>  };
>  
>  static struct c2c_dimension dim_dcacheline_mem_region = {
> -	.header		= HEADER_LOW("Region"),
> +	.header		= HEADER_LOW("Range"),
>  	.name		= "dcacheline_mem_region",
>  	.cmp		= empty_cmp,
>  	.entry		= dcacheline_node_mem_region,
> -	.width		= 6,
> +	.width		= 5,
>  };
>  
>  static struct c2c_dimension dim_dcacheline_count = {
> @@ -1429,11 +1429,11 @@ static struct c2c_dimension dim_offset_node = {
>  };
>  
>  static struct c2c_dimension dim_offset_mem_region = {
> -	.header		= HEADER_LOW("Region"),
> +	.header		= HEADER_LOW("Range"),
>  	.name		= "offset_mem_region",
>  	.cmp		= empty_cmp,
>  	.entry		= dcacheline_node_mem_region,
> -	.width		= 6,
> +	.width		= 5,
>  };

[Severity: Low]
Does renaming this column to "Range" conflate hardware memory region IDs
with the range indices printed in the Memory Ranges table?

set_mem_region_str() formats the sampled PERF_MEM_REGION_MEM0..MEM7 bits as
numeric region IDs (0..7), whereas print_memory_ranges_info() prints each
ACPI MRRM entry with both a Range index and region IDs:

tools/perf/builtin-c2c.c:print_memory_ranges_info() {
    ...
		fprintf(out, "Range %d: [0x%016" PRIx64 "-0x%016" PRIx64 "] Node %d, local region id %u, remote region id %u\n",
			i, r->base, r->base + r->length - 1, r->node,
			r->local_region_id, r->remote_region_id);
    ...
}

When multiple physical address ranges map to the same region ID (for
example, Range 0 and Range 1 on local region id 0, and Range 2 on local
region id 1), labeling the region ID column "Range" causes a reported value
of 1 to look like Range 1 rather than region id 1.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261109004402.1403713-1-dapeng1.mi@linux.intel.com?part=5