Re: [PATCH v4 10/11] perf env: Set flag for kernel is 64-bit mode

[Leo Yan <leo.yan@linaro.org>]

Hi Arnaldo,

On Wed, Jul 14, 2021 at 11:00:44AM -0300, Arnaldo Carvalho de Melo wrote:

[...]

> > So, I wasn't suggesting to add this info to the perf.data file header,
> > just to the in-memory 'struct perf_env'.
> > 
> > And also we should avoid unconditionally initializing things that we may
> > never need, please structure it as:
> 
> Oops, forgot these:
>  
> > 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))
> >                kernel_is_64_bit = 1;
>                  env->kernel_is_64_bit = 1;
> >        else
> >                kernel_is_64_bit = 0;
>                  env->kernel_is_64_bit = 0;
> > }
> > 
> > 
> > void perf_env__init(struct perf_env *env)
> > {
> > 	...
> > 	env->kernel_is_64_bit = -1;
> > 	...
> > }
> > 
> > bool 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;
> > }

Thanks a lot for the suggestion; this is much clear for me, will spin
new patch set by following it.

Sorry for slow response due to my bandwidth was occupied by a task in
hand.

Thanks,
Leo