linux-kernel - Re: [PATCH v4 1/9] perf annotate: Skip annotating data types to lea instructions

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Message-ID: <aO6ZIQ2WwTPGWATX@x1>
Date: Tue, 14 Oct 2025 15:40:33 -0300
From: Arnaldo Carvalho de Melo <acme@...nel.org>
To: Zecheng Li <zecheng@...gle.com>
Cc: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>,
	Namhyung Kim <namhyung@...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>,
	Masami Hiramatsu <mhiramat@...nel.org>,
	Xu Liu <xliuprof@...gle.com>, linux-perf-users@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 1/9] perf annotate: Skip annotating data types to lea
 instructions

On Mon, Oct 13, 2025 at 06:15:58PM +0000, Zecheng Li wrote:
> Introduce a helper function is_address_gen_insn() to check
> arch-dependent address generation instructions like lea in x86. Remove
> type annotation on these instructions since they are not accessing
> memory. It should be counted as `no_mem_ops`.
> 
> Signed-off-by: Zecheng Li <zecheng@...gle.com>
> ---
>  tools/perf/util/annotate.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> index a2e34f149a07..fb60467fa877 100644
> --- a/tools/perf/util/annotate.c
> +++ b/tools/perf/util/annotate.c
> @@ -2698,6 +2698,20 @@ static bool is_stack_canary(struct arch *arch, struct annotated_op_loc *loc)
>  	return false;
>  }
>  
> +/**
> + * Returns true if the instruction has a memory operand without
> + * performing a load/store
> + */
> +static bool is_address_gen_insn(struct arch *arch, struct disasm_line *dl)
> +{
> +	if (arch__is(arch, "x86")) {
> +		if (!strncmp(dl->ins.name, "lea", 3))
> +			return true;
> +	}

Can't we turn this into:

tatic bool disasm_line__is_address_gen_insn(const struct disasm_line *dl)
{
		return dl->ins.address_gen;
}

I.e. at some initial step when setting dl->ins, cache this series of
string operations and then use it s result?

- Arnaldo

> +
>  static struct disasm_line *
>  annotation__prev_asm_line(struct annotation *notes, struct disasm_line *curr)
>  {
> @@ -2806,6 +2820,12 @@ __hist_entry__get_data_type(struct hist_entry *he, struct arch *arch,
>  		return &stackop_type;
>  	}
>  
> +	if (is_address_gen_insn(arch, dl)) {
> +		istat->bad++;
> +		ann_data_stat.no_mem_ops++;
> +		return NO_TYPE;
> +	}
> +
>  	for_each_insn_op_loc(&loc, i, op_loc) {
>  		struct data_loc_info dloc = {
>  			.arch = arch,
> -- 
> 2.51.0.788.g6d19910ace-goog