On 04/15/2017 02:43 AM, Steven Rostedt wrote: >> Yes, how about this? >> +If the G process has highest priority in the chain, any rightside lock owners >> +in the tree branch need to increase its' priority as high as G. > > If task G is the highest priority task in the chain, then all the tasks > up the chain (A and B in this example), must have their priorities > increased to that of G. Sounds better than mine. :) >> >> The schedule can then wake up for a couple of reasons: > > The task can then wake up for a couple of reasons: fixed. > >> 1) The previous lock owner released the lock, and we are top_waiter now > > and the task is now the top_waiter Yes. > >> 2) we received a signal or timeout >> >> For the first reason, we could get the lock in acquisition retry and back to >> TASK_RUNNING state. > > Actually that's not quite true. > > In the first case, the task will try again to acquire the lock. If it > does, then it will take itself off the waiters tree and set itself back > to the TASK_RUNNING state. If the lock was acquired by another task > before this task could get the lock, then it will go back to sleep and > wait to be woken again. Yes, your version includes the failure conditions in lock retrying. will use yours explanation, thanks! > >> For the second reason, if task is in TASK_INTERRUPTIBLE >> state, we will give up the lock acquisition, and also back to TASK_RUNNING. > > The second case is only applicable for tasks that are grabbing a mutex > that can wake up before getting the lock, either due to a signal or > a timeout (i.e. rt_mutex_timed_futex_lock()). When woken, it will try to > take the lock again, if it succeeds, then the task will return with the > lock held, otherwise it will return with -EINTR if the task was woken > by a signal, or -ETIMEDOUT if it timed out. Will use yours version too. Thanks a lot! > >> Otherwise we will yield cpu and back to sleep. > > Nuke the above sentence. Drop this sentence. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
