Re: [PATCH 3/6] perf tools: Show memory region in perf-c2c subcommand

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Missing newline character in WARN_ONCE format string.
--

--- Patch [3]: [PATCH 3/6] perf tools: Show memory region in perf-c2c subcommand ---
commit 13662f60c6b5c5739b7e7fe17ff89755ab8e651d
Author: Dapeng Mi <dapeng1.mi@linux.intel.com>

perf tools: Show memory region in perf-c2c subcommand

This commit adds a memory region field to the perf-c2c cacheline list view
to help users identify the region a cacheline belongs to. It updates the
internal structures, stats calculations, and display logic to show this
new field.

Link: https://lore.kernel.org/all/20260114011750.350569-1-dapeng1.mi@linux.intel.com/

> diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c
> index c9584dbedf77a..57e822dbd2d4a 100644
> --- a/tools/perf/builtin-c2c.c
> +++ b/tools/perf/builtin-c2c.c

[ ... ]

> @@ -281,6 +282,18 @@ static void c2c_he__set_node(struct c2c_hist_entry *c2c_he,
>  	}
>  }
>  
> +static void c2c_he__set_mem_region(struct c2c_hist_entry *c2c_he,
> +				   unsigned int mem_region)
> +{
> +	if (WARN_ONCE(mem_region > PERF_MEM_REGION_MEM7,
> +		      "WARNING: invalid memory region ID"))

[Severity: Low]
Does this WARN_ONCE format string need a trailing newline character?

In the perf tools environment, WARN_ONCE uses __WARN_printf, which maps
directly to fprintf(stderr, ...) without appending a newline. As a result,
when this warning is triggered, the subsequent output will be printed on the
same line, resulting in malformed terminal output.

> +		return;
> +
> +	/* Update mem_region only if it really accesses memory */
> +	if (mem_region >= PERF_MEM_REGION_MMIO)
> +		c2c_he->mem_region = mem_region;
> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260709221736.33446-1-thomas.falcon@intel.com?part=3