Problem of performance with RTEMS 4.6.2 / LEON 2

[DUTOIT Pascal]

Hello,

Our product uses RTEMS 4.6.2 on LEON 2 (clock : 20 MHz) with a tick of  
1 ms. In this configuration, a problem of performance appears:
- when any task uses a RTEMS directive, before calling it, the task  
stores this action in a trace, with a date/time (accuracy:1 µs).
- then, we have activated the "User Extension Manager" in which we  
connect, for instance, the task context switch managed by RTEMS. We  
store this other information into the same trace (cf.  
USER_EXTENSION_MNGR_Thread_Switch with the current task information).

By comparing these two dates, we can see what is the amount of µs  
between the RTEMS directive called by the application AND the end of  
the context switch of the current task.

We noticed this amount can reach more than 700 µs, for each call.
Some of our tasks are activated each 16 ms. If there are, for example,  
10 context switchs during a 16 ms cycle, the wasted time can reach 7 ms.

What could we do to strongly reduce this amount?
Regards

PS: Storing a trace costs 10 µs. Therefore, the instrumentation with  
this trace does not disturb the behaviour of the product and of RTEMS.


----------------------------------------------------------------

Ce message electronique et tous les fichiers joints qu'il contient  
(ci-apres "le message") sont confidentiels et destines exclusivement a  
l'usage des destinataires indiques ou des personnes dument habilitees  
a les recevoir a leur place.

Si vous recevez ce message par erreur, merci de bien vouloir le  
detruire et d'en avertir l'emetteur.

Toute utilisation de ce message non conforme a sa destination, toute  
diffusion ou toute publication totale ou partielle est interdite sauf  
autorisation expresse de l'emetteur.

Les idees et opinions exprimees dans ce message sont celles de son  
auteur et ne representent pas necessairement celles de CS  
Communication & Systemes ou de ses filiales.

Malgre toutes les dispositions prises par CS Communication & Systemes  
et ses filiales pour minimiser les risques de virus, les fichiers  
joints a ce message peuvent contenir des virus qui pourraient  
endommager votre systeme informatique. Il vous appartient d'effectuer  
vos propres controles anti-virus avant d'ouvrir les fichiers joints.  
CS Communication & Systemes et ses filiales declinent toute  
responsabilite pour toute perte ou dommage resultant de l'utilisation  
de ce message et/ou des fichiers joints.

This e-mail and any file attached hereto (hereinafter 'the e-mail')  
are confidential and intended solely for the use of the adressees  
indicated below or the persons duly entitled to receive them in their  
place.

If you receive this e-mail in error, please delete it and notify the sender.

Any use of this e-mail not in accordance with its purpose, any  
dissemination or disclosure, either whole or partial, is prohibited,  
unless formally approved by the sender.

The ideas or opinions expressed in this e-mail are solely those of its  
author and do not necessarily represent those of CS Communication &  
Systeme or its affiliates.

Despite all the measures taken by CS Communication & Systeme and its  
affiliates in order to minimize the risks of virus, the files attached  
to this e-mail may contain virus which could damage your information  
system. You are responsible for processing your own anti-virus  
checking before opening any file attached hereto. Neither CS  
Communication & Systemes, nor its affiliates, shall be held liable for  
any loss or damage due to the use of this e-mail or any file attached  
hereto.