Hi Mike,

sorry, but somehow I can't understand this patch...

I'll try to read it with a fresh head on Weekend, but for example,

On 06/01, Mike Christie wrote:
>
>  static int vhost_task_fn(void *data)
>  {
>       struct vhost_task *vtsk = data;
> -     int ret;
> +     bool dead = false;
> +
> +     for (;;) {
> +             bool did_work;
> +
> +             /* mb paired w/ vhost_task_stop */
> +             if (test_bit(VHOST_TASK_FLAGS_STOP, &vtsk->flags))
> +                     break;
> +
> +             if (!dead && signal_pending(current)) {
> +                     struct ksignal ksig;
> +                     /*
> +                      * Calling get_signal will block in SIGSTOP,
> +                      * or clear fatal_signal_pending, but remember
> +                      * what was set.
> +                      *
> +                      * This thread won't actually exit until all
> +                      * of the file descriptors are closed, and
> +                      * the release function is called.
> +                      */
> +                     dead = get_signal(&ksig);
> +                     if (dead)
> +                             clear_thread_flag(TIF_SIGPENDING);

this can't be right or I am totally confused.

Another signal_wake_up() can come right after clear(SIGPENDING).


Again, I'll try to re-read this patch, but let me ask anyway...

Do we have a plan B? I mean... iirc you have mentioned that you can
change these code paths to do something like

        if (killed)
                tell_the_drivers_that_all_callbacks_will_fail();


so that vhost_worker() can exit after get_signal() returns SIGKILL.

Probably I misunderstood you, but it would be nice to avoid the changes
in coredump/etc code just to add a temporary (iiuc!) fix.

Oleg.

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