On Wed, 5 Dec 2007, Oleg Nesterov wrote: > do_signal_stop() counts all sub-thread and sets ->group_stop_count > accordingly. > Every thread should decrement ->group_stop_count and stop, the last one should > notify the parent. > > However a sub-thread can exit before it notices the signal_pending(), or it > may > be somewhere in do_exit() already. In that case the group stop never finishes > properly. > > Note: this is a minimal fix, we can add some optimizations later. Say we can > return quickly if thread_group_empty(). Also, we can move some signal related > code from exit_notify() to exit_signals(). > > Signed-off-by: Oleg Nesterov <[EMAIL PROTECTED]>
Looks OK for me, even though we're doing more work on the exit path. OTOH I don't see a non-racy way of doing it w/out grabbing the lock. Did you try to bench how much this change costs? Anyway, looks sane to me... Acked-by: Davide Libenzi <[EMAIL PROTECTED]> - Davide -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/