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Re: AW: Problem with CPU Load Measurements and gcc-arm-eabi optimization.


Hi Richard

Thanks for the fast answer. This is a little embarrassing, I managed to find the commit you are referring to:

http://hg-pub.ecoscentric.com/ecos/rev/041821fb5427

The Version of Ecos I (have to) use is a port for the Xilinx Zynq Platform:
 https://github.com/antmicro/ecos-mars-zx3
Why they not just make a ecos package for the hal - instead of forking - I don't know (I'm quite new to the industry). Their version seems to be built on the ecos-v3 branch in which the above mentioned commit does not seem to me merged:
http://hg-pub.ecoscentric.com/ecos-v3_0-branch/file/7d8c61e6225c/packages/kernel/current/src/common/thread.cxx

So maybe I should read a bit more about the ecos release model to find out which version I should use in future.

Serafin



On 17.11.2014 18:47, Richard Rauch wrote:
Hello,

are you sure, that you are using current version of eCos?
This issue should be already solved. Current version has "volatile" keyword as you proposed!

Richard Rauch
www.itrgmbh.com


-----UrsprÃngliche Nachricht-----
Von: ecos-discuss-owner@ecos.sourceware.org [mailto:ecos-discuss-
owner@ecos.sourceware.org] Im Auftrag von lesc
Gesendet: Montag, 17. November 2014 14:07
An: eCos Discussion
Betreff: [ECOS] Problem with CPU Load Measurements and gcc-arm-eabi
optimization.

Hello Everyone

I just encountered the Problem that the cyg_cpuload_create always delivers
100% on my System. After a bit of debugging I figured out, that the whole
for-loop in idle_thread_main seems to be omitted.

I could fix this Problem with declaring
idle_thread_loops[CYGNUM_KERNEL_CPU_MAX] as volatile (patch below).
But this has maybe some consequences I am not thinking of, as the variables
are now always synced to the ram and no kept in a CPU register.

Do you see any Problem with my approach?

Regards Serafin

Patch:

  From 2799f68a5e508c6bece6ec85b1e201282983b98d Mon Sep 17 00:00:00
2001
From: Serafin Leschke <lesc@zhaw.ch>
Date: Mon, 17 Nov 2014 13:51:23 +0100
Subject: [PATCH] declare idle_thread_loops as volatile

---
   packages/kernel/current/src/common/thread.cxx | 2 +-
   1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/kernel/current/src/common/thread.cxx
b/packages/kernel/current/src/common/thread.cxx
index 86a3dc4..bd1aa99 100644
--- a/packages/kernel/current/src/common/thread.cxx
+++ b/packages/kernel/current/src/common/thread.cxx
@@ -1211,7 +1211,7 @@ Cyg_ThreadTimer::alarm(
   #endif // CYGNUM_HAL_STACK_SIZE_MINIMUM

   // Loop counter for debugging/housekeeping
-cyg_uint32 idle_thread_loops[CYGNUM_KERNEL_CPU_MAX];
+volatile cyg_uint32 idle_thread_loops[CYGNUM_KERNEL_CPU_MAX];

   static char
idle_thread_stack[CYGNUM_KERNEL_CPU_MAX][CYGNUM_KERNEL_THREA
DS_IDLE_STACK_SIZE];

--
1.9.1


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--
Serafin Leschke, BSc in Computer Sience UAS Zurich
Research Assistant

ZHAW, Zurich University of Applied Sciences
InES, Institute of Embedded Systems
Postfach
Technikumstr. 22
CH-8401 Winterthur
--
Tel: +41 58 934 69 79
Fax: +41 58 935 76 87
E-Mail: serafin.lescke@zhaw.ch
Web: http://ines.zhaw.ch
--


--
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and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss


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