On 26/06/15 01:45, Chris Johns wrote:
On 25/06/2015 11:17 pm, Sebastian Huber wrote:
The problem is that empty structures have a different size in C and C++.
---
cpukit/score/include/rtems/score/percpu.h | 17 ++-
cpukit/score/include/rtems/score/smplock.h | 167 +++++++++++++++++------------
cpukit/score/src/profilingsmplock.c | 18 ++--
cpukit/score/src/smp.c | 5 +-
4 files changed, 127 insertions(+), 80 deletions(-)
diff --git a/cpukit/score/include/rtems/score/percpu.h
b/cpukit/score/include/rtems/score/percpu.h
index a6f7a25..088c31f 100644
--- a/cpukit/score/include/rtems/score/percpu.h
+++ b/cpukit/score/include/rtems/score/percpu.h
@@ -319,10 +319,17 @@ typedef struct Per_CPU_Control {
*/
SMP_ticket_lock_Control Lock;
- /**
- * @brief Lock statistics context for the per-CPU lock.
- */
- SMP_lock_Stats_context Lock_stats_context;
+ #if defined( RTEMS_PROFILING )
+ /**
+ * @brief Lock statistics for the per-CPU lock.
+ */
+ SMP_lock_Stats Lock_stats;
+
+ /**
+ * @brief Lock statistics context for the per-CPU lock.
+ */
+ SMP_lock_Stats_context Lock_stats_context;
+ #endif
My only comment is the ability to get any SMP status is difficult. It is
either all on or you get nothing. Moving all stats related defines
inside #ifdefs and into the global RTEMS_PROFILING define make this
harder to do. This is not specifically addressing this lock stats change
but on a more general level and this change reminded me.
This patch changes nothing in terms of functionality. It just avoids
zero size structures which unfortunately are implementation-defined in C
(size is zero with GCC) and C++ (size must be non-zero and is 1 in GCC).
I looked into adding some SMP stats to top not long ago I found there
was nothing I report on unless profiling was on and if I turned on
profiling I got too much such as timing and other nice features.
I could not see how to show how many context switches each core had, how
many interrupts each core serviced.
We can enable such things individually.
I understand the desire to push the limits and not waste a single cycle
if we can help it but I actually found it difficult to know if I had SMP
built correctly and if it was working from a shell command line. I feel
we need some standard stats users can depend on that help us know things
are basically working.
Chris
Is this not something that can be done with the linker based tracing?
--
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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