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

From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Leo Yan <leo.yan@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Ingo Molnar <mingo@redhat.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
	Will Deacon <will@kernel.org>,
	Russell King <linux@armlinux.org.uk>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Mathieu Poirier <mathieu.poirier@linaro.org>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Mike Leach <mike.leach@linaro.org>,
	John Garry <john.garry@huawei.com>,
	Andi Kleen <ak@linux.intel.com>,
	Riccardo Mancini <rickyman7@gmail.com>,
	Jin Yao <yao.jin@linux.intel.com>,
	Li Huafei <lihuafei1@huawei.com>,
	coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
	linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
	Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: Re: [PATCH v1 1/3] perf env: Track kernel 64-bit mode in environment
Date: Mon, 9 Aug 2021 17:11:44 -0300	[thread overview]
Message-ID: <YRGMAHj3MUndBEUq@kernel.org> (raw)
In-Reply-To: <20210809112727.596876-2-leo.yan@linaro.org>

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@redhat.com>
> Signed-off-by: Leo Yan <leo.yan@linaro.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