linux-kernel - Re: [PATCH v1 1/3] perf env: Track kernel 64-bit mode in environment

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Message-ID: <YRGMAHj3MUndBEUq@kernel.org>
Date:   Mon, 9 Aug 2021 17:11:44 -0300
From:   Arnaldo Carvalho de Melo <acme@...nel.org>
To:     Leo Yan <leo.yan@...aro.org>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Ingo Molnar <mingo@...hat.com>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...hat.com>,
        Namhyung Kim <namhyung@...nel.org>,
        Will Deacon <will@...nel.org>,
        Russell King <linux@...linux.org.uk>,
        Catalin Marinas <catalin.marinas@....com>,
        Mathieu Poirier <mathieu.poirier@...aro.org>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Mike Leach <mike.leach@...aro.org>,
        John Garry <john.garry@...wei.com>,
        Andi Kleen <ak@...ux.intel.com>,
        Riccardo Mancini <rickyman7@...il.com>,
        Jin Yao <yao.jin@...ux.intel.com>,
        Li Huafei <lihuafei1@...wei.com>, coresight@...ts.linaro.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org,
        Arnaldo Carvalho de Melo <acme@...hat.com>
Subject: Re: [PATCH v1 1/3] perf env: Track kernel 64-bit mode in environment

Em Mon, Aug 09, 2021 at 07:27:25PM +0800, Leo Yan escreveu:
> It's useful to know that the kernel is running in 32-bit or 64-bit
> mode.  E.g. We can decide if perf tool is running in compat mode
> based on the info.
> 
> This patch adds an item "kernel_is_64_bit" into session's environment
> structure perf_env, its value is initialized based on the architecture
> string.

Thanks, applied.

- Arnaldo

 
> Suggested-by: Arnaldo Carvalho de Melo <acme@...hat.com>
> Signed-off-by: Leo Yan <leo.yan@...aro.org>
> ---
>  tools/perf/util/env.c | 24 +++++++++++++++++++++++-
>  tools/perf/util/env.h |  3 +++
>  2 files changed, 26 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
> index ab341050be46..8f7ff0035c41 100644
> --- a/tools/perf/util/env.c
> +++ b/tools/perf/util/env.c
> @@ -219,13 +219,35 @@ void perf_env__exit(struct perf_env *env)
>  	zfree(&env->hybrid_cpc_nodes);
>  }
>  
> -void perf_env__init(struct perf_env *env __maybe_unused)
> +void perf_env__init(struct perf_env *env)
>  {
>  #ifdef HAVE_LIBBPF_SUPPORT
>  	env->bpf_progs.infos = RB_ROOT;
>  	env->bpf_progs.btfs = RB_ROOT;
>  	init_rwsem(&env->bpf_progs.lock);
>  #endif
> +	env->kernel_is_64_bit = -1;
> +}
> +
> +static void perf_env__init_kernel_mode(struct perf_env *env)
> +{
> +	const char *arch = perf_env__raw_arch(env);
> +
> +	if (!strncmp(arch, "x86_64", 6) || !strncmp(arch, "aarch64", 7) ||
> +	    !strncmp(arch, "arm64", 5) || !strncmp(arch, "mips64", 6) ||
> +	    !strncmp(arch, "parisc64", 8) || !strncmp(arch, "riscv64", 7) ||
> +	    !strncmp(arch, "s390x", 5) || !strncmp(arch, "sparc64", 7))
> +		env->kernel_is_64_bit = 1;
> +	else
> +		env->kernel_is_64_bit = 0;
> +}
> +
> +int perf_env__kernel_is_64_bit(struct perf_env *env)
> +{
> +	if (env->kernel_is_64_bit == -1)
> +		perf_env__init_kernel_mode(env);
> +
> +	return env->kernel_is_64_bit;
>  }
>  
>  int perf_env__set_cmdline(struct perf_env *env, int argc, const char *argv[])
> diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
> index 6824a7423a2d..1f5175820a05 100644
> --- a/tools/perf/util/env.h
> +++ b/tools/perf/util/env.h
> @@ -61,6 +61,7 @@ struct perf_env {
>  	unsigned long long	total_mem;
>  	unsigned int		msr_pmu_type;
>  	unsigned int		max_branches;
> +	int			kernel_is_64_bit;
>  
>  	int			nr_cmdline;
>  	int			nr_sibling_cores;
> @@ -143,6 +144,8 @@ extern struct perf_env perf_env;
>  
>  void perf_env__exit(struct perf_env *env);
>  
> +int perf_env__kernel_is_64_bit(struct perf_env *env);
> +
>  int perf_env__set_cmdline(struct perf_env *env, int argc, const char *argv[]);
>  
>  int perf_env__read_cpuid(struct perf_env *env);
> -- 
> 2.25.1
> 

-- 

- Arnaldo