Re: [PATCH 14/14] perf diff: Add generic order option for compute sorting

[Namhyung Kim <namhyung@kernel.org>]

On Wed, 28 Nov 2012 14:52:49 +0100, Jiri Olsa wrote:
> Adding option 'o' to allow sorting based on the
> input file number.
[snip]
>  hist_entry__cmp_compute(struct hist_entry *left, struct hist_entry *right,
>  			int c)
>  {
> -	int i;
> +	struct hist_entry **pairs_left  = left->pairs;
> +	struct hist_entry **pairs_right = right->pairs;
> +	struct hist_entry *p_right, *p_left;
> +	static int64_t cmp;
>  
> -	for (i = 0; i < data_cnt; i++) {
> -		struct hist_entry **pairs_left  = left->pairs;
> -		struct hist_entry **pairs_right = right->pairs;
> -		struct hist_entry *p_right, *p_left;
> -		static int64_t cmp;
> +	if (!pairs_left || !pairs_right)
> +		return pairs_left ? -1 : 1;
>  
> -		if (!pairs_left || !pairs_right)
> -			return pairs_right - pairs_left;
> +	p_right = pairs_right[sort_compute];
> +	p_left  = pairs_left[sort_compute];
>  
> -		p_right = pairs_right[i];
> -		p_left  = pairs_left[i];
> +	if (!p_left || !p_right)
> +		return p_left ? -1 : 1;

What if both p_left and p_right are NULL?  Shouldn't it be move to the
next pairs?

>  
> -		if (!p_left || !p_right)
> -			return p_right - p_left;
> -
> -		/*
> -		 * If we differ, we are done, otherwise continue until all
> -		 * is processed or we find a difference.
> -		 */
> -		cmp = __hist_entry__cmp_compute(p_left, p_right, c);
> -		if (cmp)
> -			return cmp;
> -	}
> +	/*
> +	 * If we differ, we are done, otherwise continue until all
> +	 * is processed or we find a difference.
> +	 */

I guess this comment is not applied anymore.  Or we need a loop after
checking sort_compute column, right?

Thanks,
Namhyung


> +	cmp = __hist_entry__cmp_compute(p_left, p_right, c);
> +	if (cmp)
> +		return cmp;
>  
>  	return 0;
>  }
> @@ -759,6 +748,7 @@ static const struct option options[] = {
>  		   "columns '.' is reserved."),
>  	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
>  		    "Look for files with symbols relative to this directory"),
> +	OPT_UINTEGER('o', "order", &sort_compute, "Specify compute sorting."),
>  	OPT_END()
>  };
>  
> @@ -1087,6 +1077,11 @@ static int data_init(int argc, const char **argv)
>  		d->idx  = i;
>  	}
>  
> +	if (sort_compute >= (unsigned int) data_cnt) {
> +		pr_err("Order option out of limit.\n");
> +		return -EINVAL;
> +	}
> +
>  	return 0;
>  }