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

Jiri Olsa
2020-06-23T15:14:55Z

On Tue, Jun 23, 2020 at 12:03:45PM -0300, Arnaldo Carvalho de Melo wrote:
> 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?

yep, I think that's right

jirka

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