Re: [PATCH v8 03/13] perf evlist: implement control command handling functions

Arnaldo Carvalho de Melo
2020-06-23T15:03:50Z

Em Tue, Jun 23, 2020 at 04:56:01PM +0200, Jiri Olsa escreveu:
> On Wed, Jun 17, 2020 at 11:36:46AM +0300, Alexey Budankov wrote:
>
> SNIP
>
> > + memset(cmd_data, 0, data_size--);
> > +
> > + do {
> > + err = read(evlist->ctl_fd.fd, &c, 1);
> > + if (err > 0) {
> > + if (c == '\n' || c == '\0')
> > + break;
> > + cmd_data[bytes_read++] = c;
> > + if (bytes_read == data_size)
> > + break;
> > + } else {
> > + if (err == -1)
> > + pr_err("Failed to read from ctlfd %d: %m\n", evlist->ctl_fd.fd);
> > + break;
> > + }
> > + } while (1);
> > +
> > + pr_debug("Message from ctl_fd: \"%s%s\"\n", cmd_data,
> > + bytes_read == data_size ? "" : c == '\n' ? "\\n" : "\\0");
> > +
> > + if (err > 0) {
> > + if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG,
> > + strlen(EVLIST_CTL_CMD_ENABLE_TAG))) {
>
> you could use sizeof(EVLIST_CTL_CMD_ENABLE_TAG) instead, no function call

-1, as sizeof will get the \0, right?

>
> > + *cmd = EVLIST_CTL_CMD_ENABLE;
> > + } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG,
> > + strlen(EVLIST_CTL_CMD_DISABLE_TAG))) {
>
> ditto
>
> jirka
>

--

- Arnaldo