Re: [PATCH v4 2/3] perf/sdt : Support perf-list to print SDT events in a single file

Masami Hiramatsu
2014-08-28T10:54:20Z

(2014/08/28 6:50), Hemant Kumar wrote:
[...]
> +/*
> + * get_sdt_note_info(): flush the SDT notes onto stdout
> + */
> +static void get_sdt_note_info(struct list_head *start, const char *target)
> +{
> + struct sdt_note *pos;
> +
> + if (list_empty(start))
> + return;
> +
> + printf("%s :\n", target);
> + list_for_each_entry(pos, start, note_list) {
> + printf("%%%s : %s\n", pos->provider, pos->name);

Hmm, this will show

%app : marker

instead of

%app:marker

(blanks are placed around ":")
I think it should be the latter format.

> + }
> +}
> +
> +/*
> + * Error displayed in case of query of a
> + * single file for SDT markers
> + */
> +static int sdt_err(int val, const char *target)
> +{
> + switch (-val) {
> + case 0:
> + break;
> + case ENOENT:
> + /* Absence of SDT markers */
> + printf("%s : No SDT events found\n", target);

Please use pr_err or pr_warning for error messages.

> + break;
> + case EBADF:
> + printf("%s : Bad file name\n", target);
> + break;
> + default:
> + printf("%s\n", strerror(val));
> + }

And strerror_r instead of strerror (see https://lkml.org/lkml/2014/8/13/828)

> +
> + return val;
> +}
> +
> +/*
> + * cleanup_sdt_note_list() : Free the sdt note list
> + */
> +static void cleanup_sdt_note_list(struct list_head *sdt_notes)
> +{
> + struct sdt_note *tmp, *pos;
> +
> + if (list_empty(sdt_notes))
> + return;

You don't need to check this. If the list is empty list_for_each...
just skips loops.

> +
> + list_for_each_entry_safe(pos, tmp, sdt_notes, note_list) {
> + list_del(&pos->note_list);
> + free(pos->name);
> + free(pos->provider);
> + free(pos);
> + }
> +}

Thank you,

> +
> +/*
> + * filename__find_sdt() : looks for sdt markers and the list is
> + * stored in sdt_notes
> + */
> +static int filename__find_sdt(const char *target)
> +{
> + int ret;
> +
> + LIST_HEAD(sdt_notes);
> +
> + ret = get_sdt_note_list(&sdt_notes, target);
> + if (!ret)
> + get_sdt_note_info(&sdt_notes, target);
> + else
> + sdt_err(ret, target);
> +
> + cleanup_sdt_note_list(&sdt_notes);
> +
> + return ret;
> +}
> +
> +/*
> + * print_sdt_notes() : wrapper function
> + */
> +void print_sdt_events(const char *arg)
> +{
> + if (arg) {
> + filename__find_sdt(arg);
> + return;
> + }
> + pr_err("Error : File Name must be specified with \"sdt\" option!\n"
> + "Usage :\n perf list sdt <file-name>\n");
> +
> + return;
> +}
>
>

--
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com