Subject: Re: [PATCH v1] perf test expr: Fix system_tsc_freq for only x86

From: Namhyung Kim <[email-masked]>
Date: Wed, 4 Dec 2024 21:47:04 -0800

Hi Ian,

On Wed, Dec 04, 2024 at 06:23:05PM -0800, Ian Rogers wrote:
> The refactoring of tool PMU events to have a PMU then adding the expr
> literals to the tool PMU made it so that the literal system_tsc_freq
> was only supported on x86. Update the test expectations to match -
> namely the parsing is x86 specific and only yields a non-zero value on
> Intel.
> 
> Fixes: 609aa2667f67 ("perf tool_pmu: Switch to standard pmu functions and json descriptions")
> Reported-by: Athira Rajeev <[email-masked]>
> Closes: https://lore.kernel.org/linux-perf-users/[email-masked]/
> Co-developed-by: Athira Rajeev <[email-masked]>
> Signed-off-by: Ian Rogers <[email-masked]>

It failed on my VM.

  root@arm64-vm:~/build# ./perf test -v 7
  --- start ---
  test child forked, pid 2096
  Using CPUID 0x00000000000f0510
  division by zero
  syntax error
  Unrecognized literal '#system_tsc_freq'FAILED tests/expr.c:253 #system_tsc_freq == 0
  ---- end(-1) ----
    7: Simple expression parser                                        : FAILED!

> ---
>  tools/perf/tests/expr.c | 19 ++++++++++++-------
>  1 file changed, 12 insertions(+), 7 deletions(-)
> 
> diff --git a/tools/perf/tests/expr.c b/tools/perf/tests/expr.c
> index 41ff1affdfcd..726cf8d4da28 100644
> --- a/tools/perf/tests/expr.c
> +++ b/tools/perf/tests/expr.c
> @@ -75,14 +75,12 @@ static int test__expr(struct test_suite *t __maybe_unused, int subtest __maybe_u
>  	double val, num_cpus_online, num_cpus, num_cores, num_dies, num_packages;
>  	int ret;
>  	struct expr_parse_ctx *ctx;
> -	bool is_intel = false;
>  	char strcmp_cpuid_buf[256];
>  	struct perf_cpu cpu = {-1};
>  	char *cpuid = get_cpuid_allow_env_override(cpu);
>  	char *escaped_cpuid1, *escaped_cpuid2;
>  
>  	TEST_ASSERT_VAL("get_cpuid", cpuid);
> -	is_intel = strstr(cpuid, "Intel") != NULL;
>  
>  	TEST_ASSERT_EQUAL("ids_union", test_ids_union(), 0);
>  
> @@ -245,12 +243,19 @@ static int test__expr(struct test_suite *t __maybe_unused, int subtest __maybe_u
>  	if (num_dies) // Some platforms do not have CPU die support, for example s390
>  		TEST_ASSERT_VAL("#num_dies >= #num_packages", num_dies >= num_packages);
>  
> -	TEST_ASSERT_VAL("#system_tsc_freq", expr__parse(&val, ctx, "#system_tsc_freq") == 0);
> -	if (is_intel)
> -		TEST_ASSERT_VAL("#system_tsc_freq > 0", val > 0);
> -	else
> -		TEST_ASSERT_VAL("#system_tsc_freq == 0", fpclassify(val) == FP_ZERO);
>  
> +	if (expr__parse(&val, ctx, "#system_tsc_freq") == 0) {
> +		bool is_intel = strstr(cpuid, "Intel") != NULL;
> +
> +		if (is_intel)
> +			TEST_ASSERT_VAL("#system_tsc_freq > 0", val > 0);

Also Sasha reported that some (Intel?) guest machine doesn't have TSC
frequency.

Thanks,
Namhyung

> +		else
> +			TEST_ASSERT_VAL("#system_tsc_freq == 0", fpclassify(val) == FP_ZERO);
> +	} else {
> +#if defined(__i386__) || defined(__x86_64__)
> +		TEST_ASSERT_VAL("#system_tsc_freq unsupported", 0);
> +#endif
> +	}
>  	/*
>  	 * Source count returns the number of events aggregating in a leader
>  	 * event including the leader. Check parsing yields an id.
> -- 
> 2.47.0.338.g60cca15819-goog
>