Re: [PATCH V2] trace-cmd: add option to group like comms for profile

[Steven Rostedt <rostedt@goodmis.org>]

On Thu, 21 May 2015 13:30:08 -0400
Josef Bacik <jbacik@fb.com> wrote:


> +static int compare_groups(const void *a, const void *b)
> +{
> +	const char *A = a;
> +	const char *B = b;
> +
> +	return strcmp(A, B);

a and b are not strings here. They are group_data pointers.

I think what you want is this:

static int compare_groups(const void *a, const void *b)
{
	struct group_data * const *A = a;
	struct group_data * const *B = b;

	return strcmp((*A)->comm, (*B)->comm);
}

-- Steve

> +}
> +
> 


> +static void output_groups(struct handle_data *h)
> +{
> +	struct trace_hash_item **bucket;
> +	struct trace_hash_item *item;
> +	struct group_data **groups;
> +	int nr_groups = 0;
> +	int i;
> +
> +	trace_hash_for_each_bucket(bucket, &h->group_hash) {
> +		trace_hash_for_each_item(item, bucket) {
> +			nr_groups++;
> +		}
> +	}
> +
> +	if (nr_groups == 0)
> +		return;
> +
> +	groups = malloc_or_die(sizeof(*groups) * nr_groups);
> +
> +	nr_groups = 0;
> +
> +	trace_hash_for_each_bucket(bucket, &h->group_hash) {
> +		trace_hash_while_item(item, bucket) {
> +			groups[nr_groups++] = group_from_item(item);
> +			trace_hash_del(item);
> +		}
> +	}
> +
> +	qsort(groups, nr_groups, sizeof(*groups), compare_groups);
> +
> +	for (i = 0; i < nr_groups; i++) {
> +		output_group(h, groups[i]);
> +		free_group(groups[i]);
> +	}
> +
> +	free(groups);
> +}
> +
>