On 02/22/2014 11:02 PM, Chris Johns wrote:
On 19/02/2014 7:52 pm, Sebastian Huber wrote:
Module: rtems
Branch: master
Commit: 282bfd3b41e3725ac9f5fb08b1e391af02572f4f
Changeset:
http://git.rtems.org/rtems/commit/?id=282bfd3b41e3725ac9f5fb08b1e391af02572f4f
Author: Sebastian Huber <sebastian.hu...@embedded-brains.de>
Date: Tue Feb 18 13:03:27 2014 +0100
score: Move _SMP_Handler_initialize()
---
cpukit/score/src/percpu.c | 31 -------------------------------
cpukit/score/src/smp.c | 22 ++++++++++++++++++++++
2 files changed, 22 insertions(+), 31 deletions(-)
diff --git a/cpukit/score/src/percpu.c b/cpukit/score/src/percpu.c
index aa95aa9..c68f378 100644
--- a/cpukit/score/src/percpu.c
+++ b/cpukit/score/src/percpu.c
@@ -18,40 +18,9 @@
#include "config.h"
#endif
-#include <rtems/system.h>
-#include <rtems/score/address.h>
-#include <rtems/score/thread.h>
#include <rtems/score/percpu.h>
-#include <rtems/score/wkspace.h>
-#include <rtems/config.h>
-#include <string.h>
#if defined(RTEMS_SMP)
-
- #include <rtems/score/smp.h>
-
- void _SMP_Handler_initialize(void)
- {
- uint32_t max_cpus = rtems_configuration_get_maximum_processors();
- uint32_t cpu;
-
- /*
- * Discover and initialize the secondary cores in an SMP system.
- */
- max_cpus = _CPU_SMP_Initialize( max_cpus );
-
- _SMP_Processor_count = max_cpus;
-
- for ( cpu = 1 ; cpu < max_cpus; ++cpu ) {
- const Per_CPU_Control *per_cpu = _Per_CPU_Get_by_index( cpu );
-
- _Per_CPU_Wait_for_state(
- per_cpu,
- PER_CPU_STATE_READY_TO_BEGIN_MULTITASKING
- );
- }
- }
-
void _Per_CPU_Change_state(
Per_CPU_Control *per_cpu,
Per_CPU_State new_state
diff --git a/cpukit/score/src/smp.c b/cpukit/score/src/smp.c
index 86116da..bfd77dc 100644
--- a/cpukit/score/src/smp.c
+++ b/cpukit/score/src/smp.c
@@ -29,6 +29,28 @@
#include <rtems/bspIo.h>
#endif
+void _SMP_Handler_initialize( void )
+{
+ uint32_t max_cpus = rtems_configuration_get_maximum_processors();
+ uint32_t cpu;
+
+ /*
+ * Discover and initialize the secondary cores in an SMP system.
+ */
+ max_cpus = _CPU_SMP_Initialize( max_cpus );
+
+ _SMP_Processor_count = max_cpus;
+
+ for ( cpu = 1 ; cpu < max_cpus; ++cpu ) {
+ const Per_CPU_Control *per_cpu = _Per_CPU_Get_by_index( cpu );
+
+ _Per_CPU_Wait_for_state(
+ per_cpu,
+ PER_CPU_STATE_READY_TO_BEGIN_MULTITASKING
+ );
+ }
+}
I do not agree with this approach. All cores need to be present before
continuing and it forces cpu 0 to be a "boot" or "primary" processor.
This design is not symmetric.
I cannot say much more to this topic than that what I wrote here:
http://www.rtems.org/pipermail/rtems-devel/2014-February/005481.html
Yes, this boot processor index == 0 is a problem. One fundamental
problem is that exactly one processor must initialize the BSS section.
How can you enforce this in general?
The situation in this patch is a bit better:
http://www.rtems.org/pipermail/rtems-devel/2014-February/005465.html
-void _SMP_Start_multitasking_on_secondary_processor( void )
+void _SMP_Request_start_multitasking( void )
{
Per_CPU_Control *self_cpu = _Per_CPU_Get();
+ uint32_t ncpus = _SMP_Get_processor_count();
+ uint32_t cpu;
+
+ _Per_CPU_State_change( self_cpu, PER_CPU_STATE_READY_TO_START_MULTITASKING );
- #if defined(RTEMS_DEBUG)
- printk( "Made it to %d -- ", _Per_CPU_Get_index( self_cpu ) );
- #endif
+ for ( cpu = 0 ; cpu < ncpus ; ++cpu ) {
+ Per_CPU_Control *per_cpu = _Per_CPU_Get_by_index( cpu );
+
+ _Per_CPU_State_change( per_cpu, PER_CPU_STATE_REQUEST_START_MULTITASKING );
+ }
+}
Please notice that this loop starts with cpu = 0.
At the moment I can offer only this patch. It is an improvement since
now the shutdown works. There are so many problems and things to do on
SMP so that I have to focus. I cannot fix everything at once and now.
--
Sebastian Huber, embedded brains GmbH
Address : Dornierstr. 4, D-82178 Puchheim, Germany
Phone : +49 89 189 47 41-16
Fax : +49 89 189 47 41-09
E-Mail : sebastian.hu...@embedded-brains.de
PGP : Public key available on request.
Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
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