[PATCH 1/3] Enhancement of the RMS manager for the overrun handling.
Kuan-Hsun Chen
c0066c at gmail.com
Wed Dec 21 16:42:39 UTC 2016
Three additional functions:
RM_Postponed_num, RM_Renew_deadline, and RM_Release_postponedjob.
Four refined functions:
RM_Activate, RM_Block_while_expired, rtems_rate_monotonic_period, RM_Timeout.
Rate_monotonic_Control contains one counter for counting the postponed jobs and one for recording the recent deadline.
---
cpukit/rtems/include/rtems/rtems/ratemon.h | 33 +++++++
cpukit/rtems/include/rtems/rtems/ratemonimpl.h | 13 +++
cpukit/rtems/src/ratemonperiod.c | 128 +++++++++++++++++++++++--
cpukit/rtems/src/ratemontimeout.c | 11 ++-
4 files changed, 176 insertions(+), 9 deletions(-)
diff --git a/cpukit/rtems/include/rtems/rtems/ratemon.h b/cpukit/rtems/include/rtems/rtems/ratemon.h
index 50b8478..17b2ebf 100644
--- a/cpukit/rtems/include/rtems/rtems/ratemon.h
+++ b/cpukit/rtems/include/rtems/rtems/ratemon.h
@@ -18,10 +18,12 @@
* - delete a rate monotonic timer
* - conclude current and start the next period
* - obtain status information on a period
+ * - obtain the number of postponed jobs
*/
/* COPYRIGHT (c) 1989-2009, 2016.
* On-Line Applications Research Corporation (OAR).
+ * COPYRIGHT (c) 2016 Kuan-Hsun Chen.
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
@@ -240,6 +242,18 @@ typedef struct {
* This field contains the statistics maintained for the period.
*/
Rate_monotonic_Statistics Statistics;
+
+ /**
+ * This field contains the number of postponed jobs.
+ * When the watchdog timeout, this variable will be increased immediately.
+ */
+ uint32_t postponed_jobs;
+
+ /**
+ * This field contains the tick of the latest deadline decided by the period
+ * watchdog.
+ */
+ uint64_t latest_deadline;
} Rate_monotonic_Control;
/**
@@ -403,6 +417,25 @@ rtems_status_code rtems_rate_monotonic_period(
rtems_interval length
);
+/**
+ * @brief RTEMS Return the number of postponed jobs
+ *
+ * This is a helper function for runtime monitoring to return
+ * the number of postponed jobs in this given period. This number
+ * is only increased by the corresponding watchdog,
+ * and is decreased by RMS manager with the postponed job releasing.
+ *
+ * @param[in] id is the period id
+ *
+ * @retval This helper function returns the number of postponed
+ * jobs with a given period_id.
+ *
+ */
+uint32_t rtems_rate_monotonic_postponed_num(
+ rtems_id period_id
+);
+
+
/**@}*/
#ifdef __cplusplus
diff --git a/cpukit/rtems/include/rtems/rtems/ratemonimpl.h b/cpukit/rtems/include/rtems/rtems/ratemonimpl.h
index b6b3ffd..c67586b 100644
--- a/cpukit/rtems/include/rtems/rtems/ratemonimpl.h
+++ b/cpukit/rtems/include/rtems/rtems/ratemonimpl.h
@@ -9,6 +9,7 @@
/* COPYRIGHT (c) 1989-2008.
* On-Line Applications Research Corporation (OAR).
* Copyright (c) 2016 embedded brains GmbH.
+ * COPYRIGHT (c) 2016 Kuan-Hsun Chen.
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
@@ -116,6 +117,18 @@ bool _Rate_monotonic_Get_status(
Timestamp_Control *cpu_since_last_period
);
+/**
+ * @brief Renew the watchdog deadline
+ *
+ * This routine is prepared for the watchdog timeout to renew its deadline
+ * without releasing jobs.
+ */
+void _Rate_monotonic_Renew_deadline(
+ Rate_monotonic_Control *the_period,
+ Thread_Control *owner,
+ ISR_lock_Context *lock_context
+);
+
void _Rate_monotonic_Restart(
Rate_monotonic_Control *the_period,
Thread_Control *owner,
diff --git a/cpukit/rtems/src/ratemonperiod.c b/cpukit/rtems/src/ratemonperiod.c
index 77bd996..28ac810 100644
--- a/cpukit/rtems/src/ratemonperiod.c
+++ b/cpukit/rtems/src/ratemonperiod.c
@@ -9,6 +9,7 @@
* COPYRIGHT (c) 1989-2010.
* On-Line Applications Research Corporation (OAR).
* Copyright (c) 2016 embedded brains GmbH.
+ * COPYRIGHT (c) 2016 Kuan-Hsun Chen.
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
@@ -63,6 +64,32 @@ bool _Rate_monotonic_Get_status(
return true;
}
+static void _Rate_monotonic_Release_postponedjob(
+ Rate_monotonic_Control *the_period,
+ Thread_Control *owner,
+ rtems_interval next_length,
+ ISR_lock_Context *lock_context
+)
+{
+ /* This function only releases the postponed jobs. */
+ Per_CPU_Control *cpu_self;
+ Thread_queue_Context queue_context;
+ cpu_self = _Thread_Dispatch_disable_critical( lock_context );
+ _Rate_monotonic_Release( owner, lock_context );
+
+ the_period->postponed_jobs -=1;
+ _Scheduler_Release_job(
+ owner,
+ &the_period->Priority,
+ the_period->latest_deadline,
+ &queue_context
+ );
+
+ _Rate_monotonic_Release( the_period, lock_context );
+ _Thread_Priority_update( &queue_context );
+ _Thread_Dispatch_enable( cpu_self );
+}
+
static void _Rate_monotonic_Release_job(
Rate_monotonic_Control *the_period,
Thread_Control *owner,
@@ -93,6 +120,30 @@ static void _Rate_monotonic_Release_job(
_Thread_Dispatch_enable( cpu_self );
}
+void _Rate_monotonic_Renew_deadline(
+ Rate_monotonic_Control *the_period,
+ Thread_Control *owner,
+ ISR_lock_Context *lock_context
+)
+{
+ Per_CPU_Control *cpu_self;
+ uint64_t deadline;
+
+ cpu_self = _Thread_Dispatch_disable_critical( lock_context );
+ _Rate_monotonic_Release( owner, lock_context );
+
+ _ISR_lock_ISR_disable( lock_context );
+ deadline = _Watchdog_Per_CPU_insert_relative(
+ &the_period->Timer,
+ cpu_self,
+ the_period->next_length
+ );
+ the_period->latest_deadline = deadline;
+ _ISR_lock_ISR_enable( lock_context );
+ _Thread_Dispatch_enable( cpu_self );
+
+}
+
void _Rate_monotonic_Restart(
Rate_monotonic_Control *the_period,
Thread_Control *owner,
@@ -190,6 +241,7 @@ static rtems_status_code _Rate_monotonic_Activate(
ISR_lock_Context *lock_context
)
{
+ the_period->postponed_jobs = 0;
the_period->state = RATE_MONOTONIC_ACTIVE;
the_period->next_length = length;
_Rate_monotonic_Restart( the_period, executing, lock_context );
@@ -241,6 +293,11 @@ static rtems_status_code _Rate_monotonic_Block_while_active(
return RTEMS_SUCCESSFUL;
}
+/*
+ * There are two possible cases: one is that the previous deadline is missed,
+ * The other is that the number of postponed jobs is not 0, but the current
+ * deadline is still not expired, i.e., state = RATE_MONOTONIC_ACTIVE.
+ */
static rtems_status_code _Rate_monotonic_Block_while_expired(
Rate_monotonic_Control *the_period,
rtems_interval length,
@@ -248,18 +305,43 @@ static rtems_status_code _Rate_monotonic_Block_while_expired(
ISR_lock_Context *lock_context
)
{
+ /*
+ * No matter the just finished jobs in time or not,
+ * they are actually missing their deadlines already.
+ */
+ the_period->state = RATE_MONOTONIC_EXPIRED;
+
/*
- * Update statistics from the concluding period
+ * Update statistics from the concluding period
*/
_Rate_monotonic_Update_statistics( the_period );
the_period->state = RATE_MONOTONIC_ACTIVE;
the_period->next_length = length;
- _Rate_monotonic_Release_job( the_period, executing, length, lock_context );
+ _Rate_monotonic_Release_postponedjob( the_period, executing, length, lock_context );
return RTEMS_TIMEOUT;
}
+/*
+ * This helper function is prepared for run-time monitoring.
+ */
+uint32_t rtems_rate_monotonic_postponed_num(
+ rtems_id period_id
+)
+{
+ Rate_monotonic_Control *the_period;
+ ISR_lock_Context lock_context;
+ Thread_Control *owner;
+
+ the_period = _Rate_monotonic_Get( period_id, &lock_context );
+ _Assert( the_period != NULL );
+ uint32_t jobs = the_period->postponed_jobs;
+ owner = the_period->owner;
+ _Rate_monotonic_Release( owner, &lock_context );
+ return jobs;
+}
+
rtems_status_code rtems_rate_monotonic_period(
rtems_id id,
rtems_interval length
@@ -292,12 +374,34 @@ rtems_status_code rtems_rate_monotonic_period(
} else {
switch ( state ) {
case RATE_MONOTONIC_ACTIVE:
- status = _Rate_monotonic_Block_while_active(
- the_period,
- length,
- executing,
- &lock_context
- );
+
+ if( the_period->postponed_jobs > 0 ){
+ /*
+ * If the number of postponed jobs is not 0, it means the
+ * previous postponed instance is finished without exceeding
+ * the current period deadline.
+ *
+ * Do nothing on the watchdog deadline assignment but release the next
+ * remaining postponed job.
+ */
+ status = _Rate_monotonic_Block_while_expired(
+ the_period,
+ length,
+ executing,
+ &lock_context
+ );
+ }else{
+ /*
+ * Normal case that no postponed jobs and no expiration, so wait for the period
+ * and update the deadline of watchdog accordingly.
+ */
+ status = _Rate_monotonic_Block_while_active(
+ the_period,
+ length,
+ executing,
+ &lock_context
+ );
+ }
break;
case RATE_MONOTONIC_INACTIVE:
status = _Rate_monotonic_Activate(
@@ -308,6 +412,14 @@ rtems_status_code rtems_rate_monotonic_period(
);
break;
default:
+ /*
+ * As now this period was already TIMEOUT, there must be at least one
+ * postponed job recorded by the watchdog. The one which exceeded
+ * the previous deadlines was just finished.
+ *
+ * Maybe there is more than one job postponed due to the preemption or
+ * the previous finished job.
+ */
_Assert( state == RATE_MONOTONIC_EXPIRED );
status = _Rate_monotonic_Block_while_expired(
the_period,
diff --git a/cpukit/rtems/src/ratemontimeout.c b/cpukit/rtems/src/ratemontimeout.c
index e514a31..f877e99 100644
--- a/cpukit/rtems/src/ratemontimeout.c
+++ b/cpukit/rtems/src/ratemontimeout.c
@@ -9,6 +9,8 @@
* COPYRIGHT (c) 1989-2009.
* On-Line Applications Research Corporation (OAR).
*
+ * COPYRIGHT (c) 2016 Kuan-Hsun Chen.
+ *
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
@@ -62,7 +64,14 @@ void _Rate_monotonic_Timeout( Watchdog_Control *the_watchdog )
_Thread_Unblock( owner );
}
} else {
+ /*
+ * If the watchdog is timeout, it means there is an additional postponed
+ * job in the next period but it is not available to release now:
+ * Either the current task is still executed, or it is preemptive by the
+ * other higher priority tasks.
+ */
+ the_period->postponed_jobs += 1;
the_period->state = RATE_MONOTONIC_EXPIRED;
- _Rate_monotonic_Release( the_period, &lock_context );
+ _Rate_monotonic_Renew_deadline( the_period, owner, &lock_context );
}
}
--
1.9.1
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