Re: [PATCH V2 3/5] perf stat: Support per-die aggregation

[Liang, Kan]

On 6/3/2019 12:36 PM, Jiri Olsa wrote:
> On Thu, May 30, 2019 at 07:53:47AM -0700, kan.liang@xxxxxxxxxxxxxxx wrote:
>
> SNIP
>
> > +
> >   static int perf_env__get_core(struct cpu_map *map, int idx, void *data)
> >   {
> >   	struct perf_env *env = data;
> >   	int core = -1, cpu = perf_env__get_cpu(env, map, idx);
> >   
> >   	if (cpu != -1) {
> > -		int socket_id = env->cpu[cpu].socket_id;
> > -
> >   		/*
> > -		 * Encode socket in upper 16 bits
> > -		 * core_id is relative to socket, and
> > +		 * Encode socket in upper 24 bits
>
> please note we use upper 8 bits for socket number,
> the comments suggests it's 24 bits

I will fix it in v3.

> > +		 * encode die id in upper 16 bits
> > +		 * core_id is relative to socket and die,
> >   		 * we need a global id. So we combine
> > -		 * socket + core id.
> > +		 * socket + die id + core id
> >   		 */
> > -		core = (socket_id << 16) | (env->cpu[cpu].core_id & 0xffff);
> > +		if (WARN_ONCE(env->cpu[cpu].socket_id >> 8,
> > +		    "The socket_id number is too big. Please upgrade the perf tool.\n"))
>
> hum, how's perf tool upgrade going to help in here?


I think there is nothing we can do for current encoding, if the socket 
number or die number is bigger than 8 bits. We have to design a new 
encoding method, which needs to update the perf tool.
So I use a similar expression from process_cpu_topology().
		if (do_core_id_test && nr != (u32)-1 && nr > (u32)cpu_nr) {
			pr_debug("socket_id number is too big."
				 "You may need to upgrade the perf tool.\n");
			goto free_cpu;
		}

Any suggestions for the warning message?



> > +			return -1;
> > +
> > +		if (WARN_ONCE(env->cpu[cpu].die_id >> 8,
> > +		    "The die_id number is too big. Please upgrade the perf tool.\n"))
> > +			return -1;
> > +
> > +		core = (env->cpu[cpu].socket_id << 24) |
> > +		       (env->cpu[cpu].die_id << 16) |
> > +		       (env->cpu[cpu].core_id & 0xffff);
> >   	}
>
> other than comments above, the patchset looks good to me

Thanks for the review. I will send out V3 after the comments are addressed.

Thanks,
Kan