On Mon, 2012-08-20 at 18:10 +0200, Oleg Nesterov wrote: > task->task_works points to the last node in the circular single-linked list, > task_work_add() adds the new element after the last one and updates > task->task_works. This is O(1).
Agreed, the way I was looking at that is: ->task_works points to the head and we put a new one in front, that too is O(1) ;-) > > > But the list should be short, we can reverse it in _run() if we change > > > task_work_add() to add to the head. > > > > Reversing a (single linked) list is O(n^2).. > > Hmm. This is O(n). You can simply iterate over this list once, changing > the ->next pointer to point back. OK, I'm going to stop and step away from the computer now.. clearly I more than useless today :/ But yeah.. that could be done. Anyway, would taking ->pi_lock over _cancel and _run suffice? -- 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/
