linux-kernel - Re: [PATCH] perf tools: Dump callchain context marker names

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Message-ID: <aVhJRW9URWItj2fh@google.com>
Date: Fri, 2 Jan 2026 14:40:05 -0800
From: Namhyung Kim <namhyung@...nel.org>
To: James Clark <james.clark@...aro.org>
Cc: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Mark Rutland <mark.rutland@....com>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
	Jiri Olsa <jolsa@...nel.org>, Ian Rogers <irogers@...gle.com>,
	Adrian Hunter <adrian.hunter@...el.com>, Leo Yan <leo.yan@....com>,
	linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] perf tools: Dump callchain context marker names

Hi James,

Happy new year!

On Fri, Jan 02, 2026 at 12:15:43PM +0000, James Clark wrote:
> These are hard to interpret in the raw output because they are printed
> as hex but are defined in perf_event.h as decimal. Make it much easier
> to read the raw callchains by just printing their names.
> 
> For example:
> 
>   $ perf report -D
> 
>   1798195372321 0x4638 [0xb0]: PERF_RECORD_SAMPLE(IP, 0x4002): 44922/44922: 0x7c8046dd3400 period: 120218 addr: 0
>   ... FP chain: nr:12
>   .....  0: fffffffffffffe00 (PERF_CONTEXT_USER)
>   .....  1: 00007c8046dd3400
>   .....  2: 00007c8046db86d3
> 
> Signed-off-by: James Clark <james.clark@...aro.org>
> ---
>  tools/perf/util/session.c | 25 +++++++++++++++++++++++--
>  1 file changed, 23 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
> index 4236503c8f6c..e812f8954075 100644
> --- a/tools/perf/util/session.c
> +++ b/tools/perf/util/session.c
> @@ -841,6 +841,26 @@ static void callchain__lbr_callstack_printf(struct perf_sample *sample)
>  	}
>  }
>  
> +static const char *callchain_context_str(u64 ip)
> +{
> +	switch (ip) {
> +	case PERF_CONTEXT_HV:
> +		return " (PERF_CONTEXT_HV)";
> +	case PERF_CONTEXT_KERNEL:
> +		return " (PERF_CONTEXT_KERNEL)";
> +	case PERF_CONTEXT_USER:
> +		return " (PERF_CONTEXT_USER)";

We now have PERF_CONTEXT_USER_DEFERRED too.

Thanks,
Namhyung


> +	case PERF_CONTEXT_GUEST:
> +		return " (PERF_CONTEXT_GUEST)";
> +	case PERF_CONTEXT_GUEST_KERNEL:
> +		return " (PERF_CONTEXT_GUEST_KERNEL)";
> +	case PERF_CONTEXT_GUEST_USER:
> +		return " (PERF_CONTEXT_GUEST_USER)";
> +	default:
> +		return "";
> +	}
> +}
> +
>  static void callchain__printf(struct evsel *evsel,
>  			      struct perf_sample *sample)
>  {
> @@ -853,8 +873,9 @@ static void callchain__printf(struct evsel *evsel,
>  	printf("... FP chain: nr:%" PRIu64 "\n", callchain->nr);
>  
>  	for (i = 0; i < callchain->nr; i++)
> -		printf("..... %2d: %016" PRIx64 "\n",
> -		       i, callchain->ips[i]);
> +		printf("..... %2d: %016" PRIx64 "%s\n",
> +		       i, callchain->ips[i],
> +		       callchain_context_str(callchain->ips[i]));
>  
>  	if (sample->deferred_callchain)
>  		printf("...... (deferred)\n");
> 
> ---
> base-commit: cbd41c6d4c26c161a2b0e70ad411d3885ff13507
> change-id: 20260102-james-perf-dump-callchain-markers-64d175b108c8
> 
> Best regards,
> -- 
> James Clark <james.clark@...aro.org>
>