Re: [PATCH v12 09/16] perf record: Introduce bytes written stats

[Jiri Olsa <jolsa@redhat.com>]

On Tue, Nov 23, 2021 at 05:08:05PM +0300, Alexey Bayduraev wrote:
> Introduce a function to calculate the total amount of data written
> and use it to support the --max-size option.
> 
> Acked-by: Namhyung Kim <namhyung@kernel.org>
> Reviewed-by: Riccardo Mancini <rickyman7@gmail.com>
> Tested-by: Riccardo Mancini <rickyman7@gmail.com>
> Signed-off-by: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
> ---
>  tools/perf/builtin-record.c | 21 ++++++++++++++++++---
>  1 file changed, 18 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index ce660691df1d..cd4f74c311e8 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -108,6 +108,7 @@ struct record_thread {
>  	struct record		*rec;
>  	unsigned long long	samples;
>  	unsigned long		waking;
> +	u64			bytes_written;
>  };
>  
>  static __thread struct record_thread *thread;
> @@ -191,10 +192,22 @@ static bool switch_output_time(struct record *rec)
>  	       trigger_is_ready(&switch_output_trigger);
>  }
>  
> +static u64 record__bytes_written(struct record *rec)
> +{
> +	int t;
> +	u64 bytes_written = rec->bytes_written;
> +	struct record_thread *thread_data = rec->thread_data;
> +
> +	for (t = 0; t < rec->nr_threads; t++)
> +		bytes_written += thread_data[t].bytes_written;
> +
> +	return bytes_written;
> +}
> +
>  static bool record__output_max_size_exceeded(struct record *rec)
>  {
>  	return rec->output_max_size &&
> -	       (rec->bytes_written >= rec->output_max_size);
> +	       (record__bytes_written(rec) >= rec->output_max_size);
>  }
>  
>  static int record__write(struct record *rec, struct mmap *map __maybe_unused,
> @@ -210,13 +223,15 @@ static int record__write(struct record *rec, struct mmap *map __maybe_unused,
>  		return -1;
>  	}
>  
> -	if (!(map && map->file))
> +	if (map && map->file)
> +		thread->bytes_written += size;
> +	else
>  		rec->bytes_written += size;

ok, that's why ;-) do we actually stil need rec->bytes_written?
can't we count that under synthesizing main thread->bytes_written?

jirka

>  
>  	if (record__output_max_size_exceeded(rec) && !done) {
>  		fprintf(stderr, "[ perf record: perf size limit reached (%" PRIu64 " KB),"
>  				" stopping session ]\n",
> -				rec->bytes_written >> 10);
> +				record__bytes_written(rec) >> 10);
>  		done = 1;
>  	}
>  
> -- 
> 2.19.0
>