From 3d6ebde1acab61e7c8fce1a1ed51517f7c2bf7c6 Mon Sep 17 00:00:00 2001 From: Sebastian Huber Date: Fri, 15 Oct 2021 11:21:31 +0200 Subject: score: Add SMP scheduler make/clean sticky This patch fixes the following broken behaviour: While a thread is scheduled on a helping scheduler, while it does not own a MrsP semaphore, if it obtains a MrsP semaphore, then no scheduler node using an idle thread and the ceiling priority of the semaphore is unblocked for the home scheduler. This could lead to priority inversion issues and is not in line with the MrsP protocol. Introduce two new scheduler operations which are only enabled if RTEMS_SMP is defined. The operations are used to make the scheduler node of the home scheduler sticky and to clean the sticky property. This helps to keep the sticky handing out of the frequently used priority update operation. Close #4532. --- cpukit/include/rtems/score/schedulerprioritysmp.h | 32 +++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'cpukit/include/rtems/score/schedulerprioritysmp.h') diff --git a/cpukit/include/rtems/score/schedulerprioritysmp.h b/cpukit/include/rtems/score/schedulerprioritysmp.h index fe314fb05b..9ece9ae143 100644 --- a/cpukit/include/rtems/score/schedulerprioritysmp.h +++ b/cpukit/include/rtems/score/schedulerprioritysmp.h @@ -93,6 +93,8 @@ typedef struct { _Scheduler_priority_SMP_Ask_for_help, \ _Scheduler_priority_SMP_Reconsider_help_request, \ _Scheduler_priority_SMP_Withdraw_node, \ + _Scheduler_priority_SMP_Make_sticky, \ + _Scheduler_priority_SMP_Clean_sticky, \ _Scheduler_default_Pin_or_unpin_not_supported, \ _Scheduler_default_Pin_or_unpin_not_supported, \ _Scheduler_priority_SMP_Add_processor, \ @@ -214,6 +216,36 @@ void _Scheduler_priority_SMP_Withdraw_node( Thread_Scheduler_state next_state ); +/** + * @brief Makes the node sticky. + * + * @param scheduler is the scheduler of the node. + * + * @param[in, out] the_thread is the thread owning the node. + * + * @param[in, out] node is the scheduler node to make sticky. + */ +void _Scheduler_priority_SMP_Make_sticky( + const Scheduler_Control *scheduler, + Thread_Control *the_thread, + Scheduler_Node *node +); + +/** + * @brief Cleans the sticky property from the node. + * + * @param scheduler is the scheduler of the node. + * + * @param[in, out] the_thread is the thread owning the node. + * + * @param[in, out] node is the scheduler node to clean the sticky property. + */ +void _Scheduler_priority_SMP_Clean_sticky( + const Scheduler_Control *scheduler, + Thread_Control *the_thread, + Scheduler_Node *node +); + /** * @brief Adds @a idle to @a scheduler. * -- cgit v1.2.3