Em Thu, Feb 11, 2021 at 05:45:38PM +0100, Jiri Olsa escreveu:
> On Thu, Feb 11, 2021 at 03:01:12PM +0900, Namhyung Kim wrote:
> > Hi Jiri,
> >
> > On Tue, Feb 9, 2021 at 5:09 AM Jiri Olsa <jo...@kernel.org> wrote:
> > > +static int daemon__reconfig(struct daemon *daemon)
> > > +{
> > > + struct daemon_session *session, *n;
> > > +
> > > + list_for_each_entry_safe(session, n, &daemon->sessions, list) {
> > > + /* No change. */
> > > + if (session->state == OK)
> > > + continue;
> > > +
> > > + /* Remove session. */
> > > + if (session->state == KILL) {
> > > + if (session->pid > 0) {
> > > + daemon_session__kill(session);
> > > + pr_info("reconfig: session '%s'
> > > killed\n", session->name);
> > > + }
> > > + daemon_session__remove(session);
> > > + continue;
> > > + }
> > > +
> > > + /* Reconfig session. */
> > > + if (session->pid > 0) {
> > > + daemon_session__kill(session);
> > > + pr_info("reconfig: session '%s' killed\n",
> > > session->name);
> > > + }
> > > + if (daemon_session__run(session, daemon))
> > > + return -1;
> >
> > Shouldn't it be 'continue'? If there's a problematic session
> > it'll prevent others from being processed. And it seems this
> > code will try to run it again and again. Maybe we can put it
> > in the KILL state (or a new FAILED state) IMHO.
>
> so if there is misconfigured session, it will get executed,
> and then we catch that it exited, like:
>
> # ./perf daemon start -f
> [2021-02-11 17:38:19.718166] daemon started (pid 1167439)
> [2021-02-11 17:38:19.719757] reconfig: ruining session
> [cycles:1167440]: abc -m 10M -e cycles --overwrite --switch-output -a
> [2021-02-11 17:38:19.720861] reconfig: ruining session [sched:1167441]:
> -m 20M -e sched:* --overwrite --switch-output -a
> [2021-02-11 17:38:21.132511] session 'cycles' exited, status=255
>
> session will be removed
>
> when the config is fixed and updated, daemon will pick it up:
>
> [2021-02-11 17:42:59.241140] reconfig: ruining session
> [cycles:1167642]: -m 10M -e cycles --overwrite --switch-output -a
>
>
> daemon_session__run fails only there's no memory for allocation,
> if mkdir fails (for other error than EEXIST) and if fork fails,
> so pretty serious errors, where we want to bail out anyway
I know you love documentation, that is why I think that it would be a
good idea to have these questions and answers in a FAQ for 'perf
daemon', don't you think? ;-)
- Arnaldo
