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

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Date:   Mon, 3 Jun 2019 18:36:36 +0200
From:   Jiri Olsa <jolsa@...hat.com>
To:     kan.liang@...ux.intel.com
Cc:     acme@...nel.org, jolsa@...nel.org, mingo@...hat.com,
        linux-kernel@...r.kernel.org, peterz@...radead.org,
        ak@...ux.intel.com
Subject: Re: [PATCH V2 3/5] perf stat: Support per-die aggregation

On Thu, May 30, 2019 at 07:53:47AM -0700, kan.liang@...ux.intel.com 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

> +		 * 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?

> +			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,
jirka