From f39f667a69cf5c4bc0dd4555537615022767f0f9 Mon Sep 17 00:00:00 2001 From: Sebastian Huber Date: Wed, 14 May 2014 13:50:48 +0200 Subject: score: Simplify _Thread_Change_priority() The function to change a thread priority was too complex. Simplify it with a new scheduler operation. This increases the average case performance due to the simplified logic. The interrupt disabled critical section is a bit prolonged since now the extract, update and enqueue steps are executed atomically. This should however not impact the worst-case interrupt latency since at least for the Deterministic Priority Scheduler this sequence can be carried out with a wee bit of instructions and no loops. Add _Scheduler_Change_priority() to replace the sequence of - _Thread_Set_transient(), - _Scheduler_Extract(), - _Scheduler_Enqueue(), and - _Scheduler_Enqueue_first(). Delete STATES_TRANSIENT, _States_Is_transient() and _Thread_Set_transient() since this state is now superfluous. With this change it is possible to get rid of the SCHEDULER_SMP_NODE_IN_THE_AIR state. This considerably simplifies the implementation of the new SMP locking protocols. --- cpukit/score/include/rtems/score/schedulercbs.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'cpukit/score/include/rtems/score/schedulercbs.h') diff --git a/cpukit/score/include/rtems/score/schedulercbs.h b/cpukit/score/include/rtems/score/schedulercbs.h index 6cfdfbe959..46db8e5609 100644 --- a/cpukit/score/include/rtems/score/schedulercbs.h +++ b/cpukit/score/include/rtems/score/schedulercbs.h @@ -52,12 +52,10 @@ extern "C" { _Scheduler_EDF_Yield, /* yield entry point */ \ _Scheduler_EDF_Block, /* block entry point */ \ _Scheduler_CBS_Unblock, /* unblock entry point */ \ + _Scheduler_EDF_Change_priority, /* change priority entry point */ \ _Scheduler_CBS_Allocate, /* allocate entry point */ \ _Scheduler_default_Free, /* free entry point */ \ _Scheduler_EDF_Update, /* update entry point */ \ - _Scheduler_EDF_Enqueue, /* enqueue entry point */ \ - _Scheduler_EDF_Enqueue_first, /* enqueue_first entry point */ \ - _Scheduler_EDF_Extract, /* extract entry point */ \ _Scheduler_EDF_Priority_compare, /* compares two priorities */ \ _Scheduler_CBS_Release_job, /* new period of task */ \ _Scheduler_default_Tick, /* tick entry point */ \ -- cgit v1.2.3