Re: please fix FUSION (Was:[v3.13][v3.14][Regression]kthread:makekthread_create()killable)

[Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>]

Thomas Gleixner wrote:
> But then systemd/udev mutters:
> 
>    "You migh be able to work around the timeout with udev rules and
>     OPTIONS+="event_timeout=120", but that code was maybe never used
>     or tested, so it might not work correctly." [1]
> 
> AFAICT from the ubuntu bug system [2] nobody bothered even to try that.
> 
> And if the udev/systemd event_timeout option is broken it's way better
> to fix that one instead of hacking random heuristics into the kernel.

I haven't tried the event_timeout= option but I think it will not work.
The timeout is hard coded as shown below and there will be no chance for taking
the event_timeout= option into account.

---------- systemd-204/src/udev/udevd.c start ----------
(...snipped...)
                        /* check for hanging events */
                        udev_list_node_foreach(loop, &worker_list) {
                                struct worker *worker = node_to_worker(loop);

                                if (worker->state != WORKER_RUNNING)
                                        continue;

                                if ((now(CLOCK_MONOTONIC) - worker->event_start_usec) > 30 * 1000 * 1000) {
                                        log_error("worker [%u] %s timeout; kill it\n", worker->pid,
                                            worker->event ? worker->event->devpath : "<idle>");
                                        kill(worker->pid, SIGKILL);
                                        worker->state = WORKER_KILLED;
                                        /* drop reference taken for state 'running' */
                                        worker_unref(worker);
                                        if (worker->event) {
                                                log_error("seq %llu '%s' killed\n",
                                                          udev_device_get_seqnum(worker->event->dev), worker->event->devpath);
                                                worker->event->exitcode = -64;
                                                event_queue_delete(worker->event, true);
                                                worker->event = NULL;
                                        }
                                }
                        }
(...snipped...)
---------- systemd-204/src/udev/udevd.c end ----------