[rtems commit] score: Fix CPU time used by executing threads
Sebastian Huber
sebh at rtems.org
Thu Mar 17 08:03:07 UTC 2016
Module: rtems
Branch: master
Commit: d37adfe5dd82cc3c933eb521b8f800c342af0e52
Changeset: http://git.rtems.org/rtems/commit/?id=d37adfe5dd82cc3c933eb521b8f800c342af0e52
Author: Sebastian Huber <sebastian.huber at embedded-brains.de>
Date: Thu Mar 3 07:02:03 2016 +0100
score: Fix CPU time used by executing threads
The CPU time used of a thread was previously maintained per-processor
mostly during _Thread_Dispatch(). However, on SMP configurations the
actual processor of a thread is difficult to figure out since thread
dispatching is a highly asynchronous process (e.g. via inter-processor
interrupts). Only the intended processor of a thread is known to the
scheduler easily. Do the CPU usage accounting during thread heir
updates in the context of the scheduler operations. Provide the
function _Thread_Get_CPU_time_used() to get the CPU usage of a thread
using proper locks to get a consistent value.
Close #2627.
---
cpukit/libcsupport/src/__times.c | 26 ++++----
cpukit/libmisc/cpuuse/cpuusagereport.c | 51 ++++++----------
cpukit/libmisc/cpuuse/cpuusagereset.c | 7 ++-
cpukit/libmisc/cpuuse/cpuusagetop.c | 23 +-------
cpukit/rtems/src/ratemonperiod.c | 75 +++++++-----------------
cpukit/score/Makefile.am | 1 +
cpukit/score/include/rtems/score/percpu.h | 15 +++--
cpukit/score/include/rtems/score/schedulerimpl.h | 32 ++++++----
cpukit/score/include/rtems/score/threadimpl.h | 67 +++++++--------------
cpukit/score/src/schedulersmpstartidle.c | 1 +
cpukit/score/src/threaddispatch.c | 5 --
cpukit/score/src/threadgetcputimeused.c | 47 +++++++++++++++
12 files changed, 157 insertions(+), 193 deletions(-)
diff --git a/cpukit/libcsupport/src/__times.c b/cpukit/libcsupport/src/__times.c
index ea6d1c6..a30f720 100644
--- a/cpukit/libcsupport/src/__times.c
+++ b/cpukit/libcsupport/src/__times.c
@@ -26,9 +26,11 @@
#include <rtems.h>
#include <sys/times.h>
-#include <time.h>
#include <sys/time.h>
-#include <errno.h>
+
+#include <string.h>
+#include <time.h>
+
#include <rtems/seterr.h>
#include <rtems/score/todimpl.h>
#include <rtems/score/timestamp.h>
@@ -42,11 +44,12 @@ clock_t _times(
)
{
rtems_interval ticks, us_per_tick;
- Thread_Control *executing;
if ( !ptms )
rtems_set_errno_and_return_minus_one( EFAULT );
+ memset( ptms, 0, sizeof( *ptms ) );
+
/*
* This call does not depend on TOD being initialized and can't fail.
*/
@@ -62,11 +65,12 @@ clock_t _times(
* this thread.
*/
{
+ Timestamp_Control cpu_time_used;
Timestamp_Control per_tick;
uint32_t ticks_of_executing;
uint32_t fractional_ticks;
- Per_CPU_Control *cpu_self;
+ _Thread_Get_CPU_time_used( _Thread_Get_executing(), &cpu_time_used );
_Timestamp_Set(
&per_tick,
rtems_configuration_get_microseconds_per_tick() /
@@ -74,25 +78,17 @@ clock_t _times(
(rtems_configuration_get_nanoseconds_per_tick() %
TOD_NANOSECONDS_PER_SECOND)
);
-
- cpu_self = _Thread_Dispatch_disable();
- executing = _Thread_Executing;
- _Thread_Update_cpu_time_used(
- executing,
- &_Thread_Time_of_last_context_switch
- );
_Timestamp_Divide(
- &executing->cpu_time_used,
+ &cpu_time_used,
&per_tick,
&ticks_of_executing,
&fractional_ticks
);
- _Thread_Dispatch_enable( cpu_self );
+
ptms->tms_utime = ticks_of_executing * us_per_tick;
}
+
ptms->tms_stime = ticks * us_per_tick;
- ptms->tms_cutime = 0;
- ptms->tms_cstime = 0;
return ticks * us_per_tick;
}
diff --git a/cpukit/libmisc/cpuuse/cpuusagereport.c b/cpukit/libmisc/cpuuse/cpuusagereport.c
index 98b5f8b..95d0648 100644
--- a/cpukit/libmisc/cpuuse/cpuusagereport.c
+++ b/cpukit/libmisc/cpuuse/cpuusagereport.c
@@ -44,7 +44,7 @@ void rtems_cpu_usage_report_with_plugin(
Objects_Information *information;
char name[13];
uint32_t ival, fval;
- Timestamp_Control uptime, total, ran, uptime_at_last_reset;
+ Timestamp_Control uptime, total, used, uptime_at_last_reset;
uint32_t seconds, nanoseconds;
if ( !print )
@@ -90,38 +90,23 @@ void rtems_cpu_usage_report_with_plugin(
name
);
- {
- Timestamp_Control last;
-
- /*
- * If this is the currently executing thread, account for time
- * since the last context switch.
- */
- ran = the_thread->cpu_time_used;
- if ( _Thread_Get_time_of_last_context_switch( the_thread, &last ) ) {
- Timestamp_Control used;
- _TOD_Get_uptime( &uptime );
- _Timestamp_Subtract( &last, &uptime, &used );
- _Timestamp_Add_to( &ran, &used );
- } else {
- _TOD_Get_uptime( &uptime );
- }
- _Timestamp_Subtract( &uptime_at_last_reset, &uptime, &total );
- _Timestamp_Divide( &ran, &total, &ival, &fval );
-
- /*
- * Print the information
- */
-
- seconds = _Timestamp_Get_seconds( &ran );
- nanoseconds = _Timestamp_Get_nanoseconds( &ran ) /
- TOD_NANOSECONDS_PER_MICROSECOND;
- (*print)( context,
- "%7" PRIu32 ".%06" PRIu32 " |%4" PRIu32 ".%03" PRIu32 "\n",
- seconds, nanoseconds,
- ival, fval
- );
- }
+ _Thread_Get_CPU_time_used( the_thread, &used );
+ _TOD_Get_uptime( &uptime );
+ _Timestamp_Subtract( &uptime_at_last_reset, &uptime, &total );
+ _Timestamp_Divide( &used, &total, &ival, &fval );
+
+ /*
+ * Print the information
+ */
+
+ seconds = _Timestamp_Get_seconds( &used );
+ nanoseconds = _Timestamp_Get_nanoseconds( &used ) /
+ TOD_NANOSECONDS_PER_MICROSECOND;
+ (*print)( context,
+ "%7" PRIu32 ".%06" PRIu32 " |%4" PRIu32 ".%03" PRIu32 "\n",
+ seconds, nanoseconds,
+ ival, fval
+ );
}
}
}
diff --git a/cpukit/libmisc/cpuuse/cpuusagereset.c b/cpukit/libmisc/cpuuse/cpuusagereset.c
index 8e9fe54..6ef50f9 100644
--- a/cpukit/libmisc/cpuuse/cpuusagereset.c
+++ b/cpukit/libmisc/cpuuse/cpuusagereset.c
@@ -21,13 +21,18 @@
#include <rtems/cpuuse.h>
#include <rtems/score/percpu.h>
#include <rtems/score/todimpl.h>
+#include <rtems/score/schedulerimpl.h>
#include <rtems/score/watchdogimpl.h>
static void CPU_usage_Per_thread_handler(
Thread_Control *the_thread
)
{
+ ISR_lock_Context lock_context;
+
+ _Scheduler_Acquire( the_thread, &lock_context );
_Timestamp_Set_to_zero( &the_thread->cpu_time_used );
+ _Scheduler_Release( the_thread, &lock_context );
}
/*
@@ -44,7 +49,7 @@ void rtems_cpu_usage_reset( void )
for ( cpu_index = 0 ; cpu_index < cpu_count ; ++cpu_index ) {
Per_CPU_Control *cpu = _Per_CPU_Get_by_index( cpu_index );
- cpu->time_of_last_context_switch = CPU_usage_Uptime_at_last_reset;
+ cpu->cpu_usage_timestamp = CPU_usage_Uptime_at_last_reset;
}
rtems_iterate_over_all_threads(CPU_usage_Per_thread_handler);
diff --git a/cpukit/libmisc/cpuuse/cpuusagetop.c b/cpukit/libmisc/cpuuse/cpuusagetop.c
index 6355e4e..9b92858 100644
--- a/cpukit/libmisc/cpuuse/cpuusagetop.c
+++ b/cpukit/libmisc/cpuuse/cpuusagetop.c
@@ -218,12 +218,14 @@ static void
task_usage(Thread_Control* thread, void* arg)
{
rtems_cpu_usage_data* data = (rtems_cpu_usage_data*) arg;
- Timestamp_Control usage = thread->cpu_time_used;
+ Timestamp_Control usage;
Timestamp_Control current = data->zero;
int j;
data->stack_size += thread->Start.Initial_stack.size;
+ _Thread_Get_CPU_time_used(thread, &usage);
+
for (j = 0; j < data->last_task_count; j++)
{
if (thread == data->last_tasks[j])
@@ -497,25 +499,6 @@ rtems_cpuusage_top_thread (rtems_task_argument arg)
current_usage = data->current_usage[i];
/*
- * If this is the currently executing thread, account for time since
- * the last context switch.
- */
- if (_Thread_Get_time_of_last_context_switch(thread, &last))
- {
- Timestamp_Control used;
- Timestamp_Control now;
-
- /*
- * Get the current uptime and assume we are not pre-empted to
- * measure the time from the last switch this thread and now.
- */
- _TOD_Get_uptime(&now);
- _Timestamp_Subtract(&last, &now, &used);
- _Timestamp_Add_to(&usage, &used);
- _Timestamp_Add_to(¤t_usage, &used);
- }
-
- /*
* Print the information
*/
print_time(data, &usage, 19);
diff --git a/cpukit/rtems/src/ratemonperiod.c b/cpukit/rtems/src/ratemonperiod.c
index 58be148..2a4b4eb 100644
--- a/cpukit/rtems/src/ratemonperiod.c
+++ b/cpukit/rtems/src/ratemonperiod.c
@@ -45,74 +45,39 @@ bool _Rate_monotonic_Get_status(
/*
* Determine cpu usage since period initiated.
*/
- used = owning_thread->cpu_time_used;
+ _Thread_Get_CPU_time_used( owning_thread, &used );
- if (owning_thread == _Thread_Executing) {
-
- Timestamp_Control ran;
-
- /* How much time time since last context switch */
- _Timestamp_Subtract(
- &_Thread_Time_of_last_context_switch, &uptime, &ran
- );
-
- /* cpu usage += ran */
- _Timestamp_Add_to( &used, &ran );
-
- /*
- * The cpu usage info was reset while executing. Can't
- * determine a status.
- */
- if (_Timestamp_Less_than(&used, &the_period->cpu_usage_period_initiated))
- return false;
+ /*
+ * The cpu usage info was reset while executing. Can't
+ * determine a status.
+ */
+ if ( _Timestamp_Less_than( &used, &the_period->cpu_usage_period_initiated ) )
+ return false;
- /* used = current cpu usage - cpu usage at start of period */
- _Timestamp_Subtract(
- &the_period->cpu_usage_period_initiated,
- &used,
- cpu_since_last_period
- );
- }
+ /* used = current cpu usage - cpu usage at start of period */
+ _Timestamp_Subtract(
+ &the_period->cpu_usage_period_initiated,
+ &used,
+ cpu_since_last_period
+ );
return true;
}
void _Rate_monotonic_Restart( Rate_monotonic_Control *the_period )
{
- Thread_Control *owning_thread = the_period->owner;
- Timestamp_Control uptime;
- ISR_Level level;
-
- _TOD_Get_uptime( &uptime );
+ ISR_Level level;
/*
* Set the starting point and the CPU time used for the statistics.
*/
- the_period->time_period_initiated = uptime;
- the_period->cpu_usage_period_initiated = owning_thread->cpu_time_used;
-
- /*
- * We need to take into account how much time the
- * executing thread has run since the last context switch. When this
- * routine is invoked from rtems_rate_monotonic_period, the owner will
- * be the executing thread. When this routine is invoked from
- * _Rate_monotonic_Timeout, it will not.
- */
- if (owning_thread == _Thread_Executing) {
- Timestamp_Control ran;
-
- /*
- * Adjust the CPU time used to account for the time since last
- * context switch.
- */
- _Timestamp_Subtract(
- &_Thread_Time_of_last_context_switch, &uptime, &ran
- );
-
- _Timestamp_Add_to( &the_period->cpu_usage_period_initiated, &ran );
- }
+ _TOD_Get_uptime( &the_period->time_period_initiated );
+ _Thread_Get_CPU_time_used(
+ the_period->owner,
+ &the_period->cpu_usage_period_initiated
+ );
- _Scheduler_Release_job( owning_thread, the_period->next_length );
+ _Scheduler_Release_job( the_period->owner, the_period->next_length );
_ISR_Disable( level );
_Watchdog_Per_CPU_insert_relative(
diff --git a/cpukit/score/Makefile.am b/cpukit/score/Makefile.am
index af78f15..b6824ad 100644
--- a/cpukit/score/Makefile.am
+++ b/cpukit/score/Makefile.am
@@ -305,6 +305,7 @@ libscore_a_SOURCES += src/thread.c src/threadchangepriority.c \
libscore_a_SOURCES += src/threadentryadaptoridle.c
libscore_a_SOURCES += src/threadentryadaptornumeric.c
libscore_a_SOURCES += src/threadentryadaptorpointer.c
+libscore_a_SOURCES += src/threadgetcputimeused.c
libscore_a_SOURCES += src/threadglobalconstruction.c
libscore_a_SOURCES += src/threadtimeout.c
libscore_a_SOURCES += src/threadyield.c
diff --git a/cpukit/score/include/rtems/score/percpu.h b/cpukit/score/include/rtems/score/percpu.h
index 2201788..95c93dd 100644
--- a/cpukit/score/include/rtems/score/percpu.h
+++ b/cpukit/score/include/rtems/score/percpu.h
@@ -333,8 +333,17 @@ typedef struct Per_CPU_Control {
*/
volatile bool dispatch_necessary;
- /** This is the time of the last context switch on this CPU. */
- Timestamp_Control time_of_last_context_switch;
+ /**
+ * @brief The CPU usage timestamp contains the time point of the last heir
+ * thread change or last CPU usage update of the executing thread of this
+ * processor.
+ *
+ * Protected by the scheduler lock.
+ *
+ * @see _Scheduler_Update_heir(), _Thread_Dispatch_update_heir() and
+ * _Thread_Get_CPU_time_used().
+ */
+ Timestamp_Control cpu_usage_timestamp;
/**
* @brief Watchdog state for this processor.
@@ -681,8 +690,6 @@ bool _Per_CPU_State_wait_for_non_initial_state(
_Per_CPU_Get()->interrupt_stack_high
#define _Thread_Dispatch_necessary \
_Per_CPU_Get()->dispatch_necessary
-#define _Thread_Time_of_last_context_switch \
- _Per_CPU_Get()->time_of_last_context_switch
/**
* @brief Returns the thread control block of the executing thread.
diff --git a/cpukit/score/include/rtems/score/schedulerimpl.h b/cpukit/score/include/rtems/score/schedulerimpl.h
index d50c36a..a41b7ea 100644
--- a/cpukit/score/include/rtems/score/schedulerimpl.h
+++ b/cpukit/score/include/rtems/score/schedulerimpl.h
@@ -627,19 +627,6 @@ bool _Scheduler_Set_affinity(
#endif /* defined(__RTEMS_HAVE_SYS_CPUSET_H__) */
-RTEMS_INLINE_ROUTINE void _Scheduler_Update_heir(
- Thread_Control *new_heir,
- bool force_dispatch
-)
-{
- Thread_Control *heir = _Thread_Heir;
-
- if ( heir != new_heir && ( heir->is_preemptible || force_dispatch ) ) {
- _Thread_Heir = new_heir;
- _Thread_Dispatch_necessary = true;
- }
-}
-
RTEMS_INLINE_ROUTINE void _Scheduler_Generic_block(
const Scheduler_Control *scheduler,
Thread_Control *the_thread,
@@ -1356,6 +1343,25 @@ RTEMS_INLINE_ROUTINE bool _Scheduler_Ask_blocked_node_for_help(
ISR_LOCK_DECLARE( extern, _Scheduler_Lock )
+RTEMS_INLINE_ROUTINE void _Scheduler_Update_heir(
+ Thread_Control *new_heir,
+ bool force_dispatch
+)
+{
+ Thread_Control *heir = _Thread_Heir;
+
+ if ( heir != new_heir && ( heir->is_preemptible || force_dispatch ) ) {
+#if defined(RTEMS_SMP)
+ /* We need this state only for _Thread_Get_CPU_time_used() */
+ _Scheduler_Thread_change_state( heir, THREAD_SCHEDULER_BLOCKED );
+ _Scheduler_Thread_change_state( new_heir, THREAD_SCHEDULER_SCHEDULED );
+#endif
+ _Thread_Update_CPU_time_used( heir, _Thread_Get_CPU( heir ) );
+ _Thread_Heir = new_heir;
+ _Thread_Dispatch_necessary = true;
+ }
+}
+
/**
* @brief Acquires the scheduler instance of the thread.
*
diff --git a/cpukit/score/include/rtems/score/threadimpl.h b/cpukit/score/include/rtems/score/threadimpl.h
index ec9851d..3f8df85 100644
--- a/cpukit/score/include/rtems/score/threadimpl.h
+++ b/cpukit/score/include/rtems/score/threadimpl.h
@@ -578,36 +578,6 @@ RTEMS_INLINE_ROUTINE bool _Thread_Is_executing_on_a_processor(
#endif
/**
- * @brief Returns @a true and sets time_of_context_switch to the
- * time of the last context switch when the thread is currently executing
- * in the system, otherwise @a false.
- */
-RTEMS_INLINE_ROUTINE bool _Thread_Get_time_of_last_context_switch(
- Thread_Control *the_thread,
- Timestamp_Control *time_of_context_switch
-)
-{
- bool retval = false;
-
- _Thread_Disable_dispatch();
- #ifndef RTEMS_SMP
- if ( _Thread_Executing->Object.id == the_thread->Object.id ) {
- *time_of_context_switch = _Thread_Time_of_last_context_switch;
- retval = true;
- }
- #else
- if ( _Thread_Is_executing_on_a_processor( the_thread ) ) {
- *time_of_context_switch =
- _Thread_Get_CPU( the_thread )->time_of_last_context_switch;
- retval = true;
- }
- #endif
- _Thread_Enable_dispatch();
- return retval;
-}
-
-
-/**
* This function returns true if the_thread is the heir
* thread, and false otherwise.
*/
@@ -803,6 +773,20 @@ RTEMS_INLINE_ROUTINE Thread_Control *_Thread_Get_heir_and_make_it_executing(
return heir;
}
+RTEMS_INLINE_ROUTINE void _Thread_Update_CPU_time_used(
+ Thread_Control *the_thread,
+ Per_CPU_Control *cpu
+)
+{
+ Timestamp_Control last;
+ Timestamp_Control ran;
+
+ last = cpu->cpu_usage_timestamp;
+ _TOD_Get_uptime( &cpu->cpu_usage_timestamp );
+ _Timestamp_Subtract( &last, &cpu->cpu_usage_timestamp, &ran );
+ _Timestamp_Add_to( &the_thread->cpu_time_used, &ran );
+}
+
#if defined( RTEMS_SMP )
RTEMS_INLINE_ROUTINE void _Thread_Dispatch_update_heir(
Per_CPU_Control *cpu_self,
@@ -810,6 +794,8 @@ RTEMS_INLINE_ROUTINE void _Thread_Dispatch_update_heir(
Thread_Control *heir
)
{
+ _Thread_Update_CPU_time_used( cpu_for_heir->heir, cpu_for_heir );
+
cpu_for_heir->heir = heir;
if ( cpu_for_heir == cpu_self ) {
@@ -820,23 +806,10 @@ RTEMS_INLINE_ROUTINE void _Thread_Dispatch_update_heir(
}
#endif
-RTEMS_INLINE_ROUTINE void _Thread_Update_cpu_time_used(
- Thread_Control *executing,
- Timestamp_Control *time_of_last_context_switch
-)
-{
- Timestamp_Control uptime;
- Timestamp_Control ran;
-
- _TOD_Get_uptime( &uptime );
- _Timestamp_Subtract(
- time_of_last_context_switch,
- &uptime,
- &ran
- );
- *time_of_last_context_switch = uptime;
- _Timestamp_Add_to( &executing->cpu_time_used, &ran );
-}
+void _Thread_Get_CPU_time_used(
+ Thread_Control *the_thread,
+ Timestamp_Control *cpu_time_used
+);
RTEMS_INLINE_ROUTINE void _Thread_Action_control_initialize(
Thread_Action_control *action_control
diff --git a/cpukit/score/src/schedulersmpstartidle.c b/cpukit/score/src/schedulersmpstartidle.c
index de125d3..0ffb628 100644
--- a/cpukit/score/src/schedulersmpstartidle.c
+++ b/cpukit/score/src/schedulersmpstartidle.c
@@ -22,6 +22,7 @@ void _Scheduler_SMP_Start_idle(
Scheduler_SMP_Context *self = _Scheduler_SMP_Get_self( context );
Scheduler_SMP_Node *node = _Scheduler_SMP_Thread_get_node( thread );
+ _Scheduler_Thread_change_state( thread, THREAD_SCHEDULER_SCHEDULED );
node->state = SCHEDULER_SMP_NODE_SCHEDULED;
_Thread_Set_CPU( thread, cpu );
diff --git a/cpukit/score/src/threaddispatch.c b/cpukit/score/src/threaddispatch.c
index 1b36c93..ce5d118 100644
--- a/cpukit/score/src/threaddispatch.c
+++ b/cpukit/score/src/threaddispatch.c
@@ -108,11 +108,6 @@ void _Thread_Do_dispatch( Per_CPU_Control *cpu_self, ISR_Level level )
_ISR_Enable( level );
#endif
- _Thread_Update_cpu_time_used(
- executing,
- &cpu_self->time_of_last_context_switch
- );
-
_User_extensions_Thread_switch( executing, heir );
_Thread_Save_fp( executing );
_Context_Switch( &executing->Registers, &heir->Registers );
diff --git a/cpukit/score/src/threadgetcputimeused.c b/cpukit/score/src/threadgetcputimeused.c
new file mode 100644
index 0000000..6bfe8ea
--- /dev/null
+++ b/cpukit/score/src/threadgetcputimeused.c
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2016 embedded brains GmbH. All rights reserved.
+ *
+ * embedded brains GmbH
+ * Dornierstr. 4
+ * 82178 Puchheim
+ * Germany
+ * <rtems at embedded-brains.de>
+ *
+ * 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.
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/score/threadimpl.h>
+#include <rtems/score/schedulerimpl.h>
+
+static bool _Thread_Is_scheduled( const Thread_Control *the_thread )
+{
+#if defined(RTEMS_SMP)
+ return the_thread->Scheduler.state == THREAD_SCHEDULER_SCHEDULED;
+#else
+ return _Thread_Is_executing( the_thread );
+#endif
+}
+
+void _Thread_Get_CPU_time_used(
+ Thread_Control *the_thread,
+ Timestamp_Control *cpu_time_used
+)
+{
+ ISR_lock_Context lock_context;
+
+ _Scheduler_Acquire( the_thread, &lock_context );
+
+ if ( _Thread_Is_scheduled( the_thread ) ) {
+ _Thread_Update_CPU_time_used( the_thread, _Thread_Get_CPU( the_thread ) );
+ }
+
+ *cpu_time_used = the_thread->cpu_time_used;
+
+ _Scheduler_Release( the_thread, &lock_context );
+}
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