[rtems commit] score: Optimize watchdog tickle
Sebastian Huber
sebh at rtems.org
Fri Feb 2 14:20:29 UTC 2018
Module: rtems
Branch: master
Commit: 89c0313938aea0618a624b7230ed29cebe723d75
Changeset: http://git.rtems.org/rtems/commit/?id=89c0313938aea0618a624b7230ed29cebe723d75
Author: Sebastian Huber <sebastian.huber at embedded-brains.de>
Date: Thu Dec 21 14:31:55 2017 +0100
score: Optimize watchdog tickle
Avoid unnecessary lock acquire/release operations. Get realtime via
timecounter only if necessary.
Update #3264.
---
cpukit/include/rtems/score/watchdogimpl.h | 32 +++++--------
cpukit/score/src/coretodset.c | 24 +++++++++-
cpukit/score/src/watchdogtick.c | 75 ++++++++++++++++++-------------
testsuites/sptests/spwatchdog/init.c | 10 ++++-
4 files changed, 86 insertions(+), 55 deletions(-)
diff --git a/cpukit/include/rtems/score/watchdogimpl.h b/cpukit/include/rtems/score/watchdogimpl.h
index f219a70..f1693d9 100644
--- a/cpukit/include/rtems/score/watchdogimpl.h
+++ b/cpukit/include/rtems/score/watchdogimpl.h
@@ -96,6 +96,13 @@ RTEMS_INLINE_ROUTINE void _Watchdog_Header_initialize(
header->first = NULL;
}
+RTEMS_INLINE_ROUTINE Watchdog_Control *_Watchdog_Header_first(
+ const Watchdog_Header *header
+)
+{
+ return (Watchdog_Control *) header->first;
+}
+
RTEMS_INLINE_ROUTINE void _Watchdog_Header_destroy(
Watchdog_Header *header
)
@@ -187,6 +194,7 @@ RTEMS_INLINE_ROUTINE void _Watchdog_Initialize(
void _Watchdog_Do_tickle(
Watchdog_Header *header,
+ Watchdog_Control *first,
uint64_t now,
#if defined(RTEMS_SMP)
ISR_lock_Control *lock,
@@ -195,11 +203,11 @@ void _Watchdog_Do_tickle(
);
#if defined(RTEMS_SMP)
- #define _Watchdog_Tickle( header, now, lock, lock_context ) \
- _Watchdog_Do_tickle( header, now, lock, lock_context )
+ #define _Watchdog_Tickle( header, first, now, lock, lock_context ) \
+ _Watchdog_Do_tickle( header, first, now, lock, lock_context )
#else
- #define _Watchdog_Tickle( header, now, lock, lock_context ) \
- _Watchdog_Do_tickle( header, now, lock_context )
+ #define _Watchdog_Tickle( header, first, now, lock, lock_context ) \
+ _Watchdog_Do_tickle( header, first, now, lock_context )
#endif
/**
@@ -548,22 +556,6 @@ RTEMS_INLINE_ROUTINE void _Watchdog_Per_CPU_remove_realtime(
);
}
-RTEMS_INLINE_ROUTINE void _Watchdog_Per_CPU_tickle_realtime(
- Per_CPU_Control *cpu,
- uint64_t now
-)
-{
- ISR_lock_Context lock_context;
-
- _ISR_lock_ISR_disable_and_acquire( &cpu->Watchdog.Lock, &lock_context );
- _Watchdog_Tickle(
- &cpu->Watchdog.Header[ PER_CPU_WATCHDOG_REALTIME ],
- now,
- &cpu->Watchdog.Lock,
- &lock_context
- );
-}
-
/** @} */
#ifdef __cplusplus
diff --git a/cpukit/score/src/coretodset.c b/cpukit/score/src/coretodset.c
index fa6407c..787c263 100644
--- a/cpukit/score/src/coretodset.c
+++ b/cpukit/score/src/coretodset.c
@@ -41,9 +41,29 @@ void _TOD_Set(
cpu_count = _SMP_Get_processor_count();
for ( cpu_index = 0 ; cpu_index < cpu_count ; ++cpu_index ) {
- Per_CPU_Control *cpu = _Per_CPU_Get_by_index( cpu_index );
+ Per_CPU_Control *cpu;
+ Watchdog_Header *header;
+ ISR_lock_Context lock_context;
+ Watchdog_Control *first;
- _Watchdog_Per_CPU_tickle_realtime( cpu, tod_as_ticks );
+ cpu = _Per_CPU_Get_by_index( cpu_index );
+ header = &cpu->Watchdog.Header[ PER_CPU_WATCHDOG_REALTIME ];
+
+ _ISR_lock_ISR_disable_and_acquire( &cpu->Watchdog.Lock, &lock_context );
+
+ first = _Watchdog_Header_first( header );
+
+ if ( first != NULL ) {
+ _Watchdog_Tickle(
+ header,
+ first,
+ tod_as_ticks,
+ &cpu->Watchdog.Lock,
+ &lock_context
+ );
+ }
+
+ _ISR_lock_Release_and_ISR_enable( &cpu->Watchdog.Lock, &lock_context );
}
_TOD.is_set = true;
diff --git a/cpukit/score/src/watchdogtick.c b/cpukit/score/src/watchdogtick.c
index 3384ea6..7a5863b 100644
--- a/cpukit/score/src/watchdogtick.c
+++ b/cpukit/score/src/watchdogtick.c
@@ -23,6 +23,7 @@
void _Watchdog_Do_tickle(
Watchdog_Header *header,
+ Watchdog_Control *first,
uint64_t now,
#ifdef RTEMS_SMP
ISR_lock_Control *lock,
@@ -30,39 +31,33 @@ void _Watchdog_Do_tickle(
ISR_lock_Context *lock_context
)
{
- while ( true ) {
- Watchdog_Control *the_watchdog;
-
- the_watchdog = (Watchdog_Control *) header->first;
-
- if ( the_watchdog == NULL ) {
- break;
- }
-
- if ( the_watchdog->expire <= now ) {
+ do {
+ if ( first->expire <= now ) {
Watchdog_Service_routine_entry routine;
- _Watchdog_Next_first( header, the_watchdog );
- _RBTree_Extract( &header->Watchdogs, &the_watchdog->Node.RBTree );
- _Watchdog_Set_state( the_watchdog, WATCHDOG_INACTIVE );
- routine = the_watchdog->routine;
+ _Watchdog_Next_first( header, first );
+ _RBTree_Extract( &header->Watchdogs, &first->Node.RBTree );
+ _Watchdog_Set_state( first, WATCHDOG_INACTIVE );
+ routine = first->routine;
_ISR_lock_Release_and_ISR_enable( lock, lock_context );
- ( *routine )( the_watchdog );
+ ( *routine )( first );
_ISR_lock_ISR_disable_and_acquire( lock, lock_context );
} else {
break;
}
- }
- _ISR_lock_Release_and_ISR_enable( lock, lock_context );
+ first = _Watchdog_Header_first( header );
+ } while ( first != NULL );
}
void _Watchdog_Tick( Per_CPU_Control *cpu )
{
- ISR_lock_Context lock_context;
- uint64_t ticks;
- struct timespec now;
+ ISR_lock_Context lock_context;
+ Watchdog_Header *header;
+ Watchdog_Control *first;
+ uint64_t ticks;
+ struct timespec now;
if ( _Per_CPU_Is_boot_processor( cpu ) ) {
++_Watchdog_Ticks_since_boot;
@@ -75,18 +70,34 @@ void _Watchdog_Tick( Per_CPU_Control *cpu )
++ticks;
cpu->Watchdog.ticks = ticks;
- _Watchdog_Tickle(
- &cpu->Watchdog.Header[ PER_CPU_WATCHDOG_MONOTONIC ],
- ticks,
- &cpu->Watchdog.Lock,
- &lock_context
- );
-
- _Timecounter_Getnanotime( &now );
- _Watchdog_Per_CPU_tickle_realtime(
- cpu,
- _Watchdog_Realtime_from_timespec( &now )
- );
+ header = &cpu->Watchdog.Header[ PER_CPU_WATCHDOG_MONOTONIC ];
+ first = _Watchdog_Header_first( header );
+
+ if ( first != NULL ) {
+ _Watchdog_Tickle(
+ header,
+ first,
+ ticks,
+ &cpu->Watchdog.Lock,
+ &lock_context
+ );
+ }
+
+ header = &cpu->Watchdog.Header[ PER_CPU_WATCHDOG_REALTIME ];
+ first = _Watchdog_Header_first( header );
+
+ if ( first != NULL ) {
+ _Timecounter_Getnanotime( &now );
+ _Watchdog_Tickle(
+ header,
+ first,
+ _Watchdog_Realtime_from_timespec( &now ),
+ &cpu->Watchdog.Lock,
+ &lock_context
+ );
+ }
+
+ _ISR_lock_Release_and_ISR_enable( &cpu->Watchdog.Lock, &lock_context );
_Scheduler_Tick( cpu );
}
diff --git a/testsuites/sptests/spwatchdog/init.c b/testsuites/sptests/spwatchdog/init.c
index 0c7d41f..5b6266d 100644
--- a/testsuites/sptests/spwatchdog/init.c
+++ b/testsuites/sptests/spwatchdog/init.c
@@ -82,10 +82,18 @@ static uint64_t test_watchdog_tick( Watchdog_Header *header, uint64_t now )
{
ISR_LOCK_DEFINE( , lock, "Test" )
ISR_lock_Context lock_context;
+ Watchdog_Control *first;
_ISR_lock_ISR_disable_and_acquire( &lock, &lock_context );
+
++now;
- _Watchdog_Tickle( header, now, &lock, &lock_context );
+ first = _Watchdog_Header_first( header );
+
+ if ( first != NULL ) {
+ _Watchdog_Tickle( header, first, now, &lock, &lock_context );
+ }
+
+ _ISR_lock_Release_and_ISR_enable( &lock, &lock_context );
_ISR_lock_Destroy( &lock );
return now;
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