Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [PATCH 3/3] task_work: use TIF_TASKWORK if available | Date | Fri, 02 Oct 2020 17:31:07 +0200 |
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On Fri, Oct 02 2020 at 17:14, Oleg Nesterov wrote: > Heh. To be honest I don't really like 1-2 ;)
I do not like any of this :)
> So I think that if we are going to add TIF_TASKWORK we should generalize > this logic and turn it into TIF_NOTIFY_SIGNAL. Similar to TIF_NOTIFY_RESUME > but implies signal_pending(). > > IOW, something like > > void set_notify_signal(task) > { > if (!test_and_set_tsk_thread_flag(task, TIF_NOTIFY_SIGNAL)) { > if (!wake_up_state(task, TASK_INTERRUPTIBLE)) > kick_process(t); > } > } > > // called by exit_to_user_mode_loop() if ti_work & _TIF_NOTIFY_SIGNAL > void tracehook_notify_signal(regs) > { > clear_thread_flag(TIF_NOTIFY_SIGNAL); > smp_mb__after_atomic(); > if (unlikely(current->task_works)) > task_work_run(); > } > > This way task_work_run() doesn't need to clear TIF_NOTIFY_SIGNAL and it can > have more users.
I think it's fundamentaly wrong that we have several places and several flags which handle task_work_run() instead of having exactly one place and one flag.
Thanks,
tglx
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