From eec08efc9048111f47f42142c30a92683bf6756c Mon Sep 17 00:00:00 2001 From: Sebastian Huber Date: Wed, 15 Jun 2016 06:59:57 +0200 Subject: posix: Rework sporadic server scheduling policy Instead of lowering the priority in case the initial budget is consumed raise the priority for each new period. Restore the normal priority once the initial budget is consumed. This makes it later easier to combine the high priority phase with temporary priority boosts (e.g. via priority ceiling and inheritance). Use the thread lock to protect the POSIX thread attributes instead of the thread state lock. This makes it easier to change the thread priority and keep the POSIX attributes consistent. Fixes a false positive use of uninitialized variable warning. --- cpukit/posix/src/pthreadcreate.c | 48 ++++++++++++++++++++++++++-------------- 1 file changed, 31 insertions(+), 17 deletions(-) (limited to 'cpukit/posix/src/pthreadcreate.c') diff --git a/cpukit/posix/src/pthreadcreate.c b/cpukit/posix/src/pthreadcreate.c index c7c233857a..f2fc1ca68e 100644 --- a/cpukit/posix/src/pthreadcreate.c +++ b/cpukit/posix/src/pthreadcreate.c @@ -60,7 +60,10 @@ int pthread_create( } }; const pthread_attr_t *the_attr; - Priority_Control core_priority; + int low_prio; + int high_prio; + Priority_Control core_low_prio; + Priority_Control core_high_prio; Thread_CPU_budget_algorithms budget_algorithm; Thread_CPU_budget_algorithm_callout budget_callout; bool is_fp; @@ -71,7 +74,7 @@ int pthread_create( int schedpolicy = SCHED_RR; struct sched_param schedparam; Objects_Name name; - int rc; + int error; ISR_lock_Context lock_context; if ( !start_routine ) @@ -130,25 +133,34 @@ int pthread_create( if ( the_attr->contentionscope != PTHREAD_SCOPE_PROCESS ) return ENOTSUP; - /* - * Interpret the scheduling parameters. - */ - if ( !_POSIX_Priority_Is_valid( schedparam.sched_priority ) ) - return EINVAL; - - core_priority = _POSIX_Priority_To_core( schedparam.sched_priority ); - - /* - * Set the core scheduling policy information. - */ - rc = _POSIX_Thread_Translate_sched_param( + error = _POSIX_Thread_Translate_sched_param( schedpolicy, &schedparam, &budget_algorithm, &budget_callout ); - if ( rc ) - return rc; + if ( error != 0 ) { + return error; + } + + if ( schedpolicy == SCHED_SPORADIC ) { + low_prio = schedparam.sched_ss_low_priority; + high_prio = schedparam.sched_priority; + } else { + low_prio = schedparam.sched_priority; + high_prio = low_prio; + } + + if ( !_POSIX_Priority_Is_valid( low_prio ) ) { + return EINVAL; + } + + if ( !_POSIX_Priority_Is_valid( high_prio ) ) { + return EINVAL; + } + + core_low_prio = _POSIX_Priority_To_core( low_prio ); + core_high_prio = _POSIX_Priority_To_core( high_prio ); #if defined(RTEMS_SMP) #if __RTEMS_HAVE_SYS_CPUSET_H__ @@ -186,7 +198,7 @@ int pthread_create( the_attr->stackaddr, _POSIX_Threads_Ensure_minimum_stack(the_attr->stacksize), is_fp, - core_priority, + core_high_prio, true, /* preemptible */ budget_algorithm, budget_callout, @@ -226,6 +238,8 @@ int pthread_create( api = the_thread->API_Extensions[ THREAD_API_POSIX ]; _POSIX_Threads_Copy_attributes( &api->Attributes, the_attr ); + api->Sporadic.low_priority = core_low_prio; + api->Sporadic.high_priority = core_high_prio; if ( schedpolicy == SCHED_SPORADIC ) { _ISR_lock_ISR_disable( &lock_context ); -- cgit v1.2.3