On Thu, Oct 22, 2015 at 01:14:16PM -0500, Tom Zanussi wrote:
> Allow users to specify keys and/or values to sort on. With this
> addition, keys and values specified using the 'keys=' and 'vals='
> keywords can be used to sort the hist trigger output via a new 'sort='
> keyword. If multiple sort keys are specified, the output will be
> sorted using the second key as a secondary sort key, etc. The default
> sort order is ascending; if the user wants a different sort order,
> '.descending' can be appended to the specific sort key. Before this
> addition, output was always sorted by 'hitcount' in ascending order.
>
> This expands the hist trigger syntax from this:
>
> # echo hist:keys=xxx:vals=yyy \
> [ if filter] > event/trigger
>
> to this:
>
> # echo hist:keys=xxx:vals=yyy:sort=zzz.descending \
> [ if filter] > event/trigger
>
> Signed-off-by: Tom Zanussi <tom.zanu...@linux.intel.com>
> Tested-by: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>
> ---
[SNIP]
> static int create_sort_keys(struct hist_trigger_data *hist_data)
> {
> + char *fields_str = hist_data->attrs->sort_key_str;
> + struct ftrace_event_field *field = NULL;
> + struct tracing_map_sort_key *sort_key;
> + unsigned int i, j;
> int ret = 0;
>
> hist_data->n_sort_keys = 1; /* sort_keys[0] is always hitcount */
This comment should be updated.
Thanks,
Namhyung
>
> + if (!fields_str)
> + goto out;
> +
> + strsep(&fields_str, "=");
> + if (!fields_str) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + for (i = 0; i < TRACING_MAP_SORT_KEYS_MAX; i++) {
> + char *field_str, *field_name;
> +
> + sort_key = &hist_data->sort_keys[i];
> +
> + field_str = strsep(&fields_str, ",");
> + if (!field_str) {
> + if (i == 0)
> + ret = -EINVAL;
> + break;
> + }
> +
> + if ((i == TRACING_MAP_SORT_KEYS_MAX - 1) && fields_str) {
> + ret = -EINVAL;
> + break;
> + }
> +
> + field_name = strsep(&field_str, ".");
> + if (!field_name) {
> + ret = -EINVAL;
> + break;
> + }
> +
> + if (!strcmp(field_name, "hitcount")) {
> + ret = is_descending(field_str);
> + if (ret < 0)
> + break;
> + sort_key->descending = ret;
> + continue;
> + }
> +
> + for (j = 1; j < hist_data->n_fields; j++) {
> + field = hist_data->fields[j]->field;
> + if (field && !strcmp(field_name, field->name)) {
> + sort_key->field_idx = j;
> + ret = is_descending(field_str);
> + if (ret < 0)
> + goto out;
> + sort_key->descending = ret;
> + break;
> + }
> + }
> + if (j == hist_data->n_fields) {
> + ret = -EINVAL;
> + break;
> + }
> + }
> + hist_data->n_sort_keys = i;
> + out:
> return ret;
> }
>
> @@ -737,7 +817,26 @@ static int event_hist_trigger_print(struct seq_file *m,
> }
>
> seq_puts(m, ":sort=");
> - seq_puts(m, "hitcount");
> +
> + for (i = 0; i < hist_data->n_sort_keys; i++) {
> + struct tracing_map_sort_key *sort_key;
> +
> + sort_key = &hist_data->sort_keys[i];
> +
> + if (i > 0)
> + seq_puts(m, ",");
> +
> + if (sort_key->field_idx == HITCOUNT_IDX)
> + seq_puts(m, "hitcount");
> + else {
> + unsigned int idx = sort_key->field_idx;
> +
> + hist_field_print(m, hist_data->fields[idx]);
> + }
> +
> + if (sort_key->descending)
> + seq_puts(m, ".descending");
> + }
>
> seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits));
>
> --
> 1.9.3
>
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