Task sync problems related with binary semaphore and cache memories

[Sebastian Huber]

On 27/11/2018 13:23, Arturo Perez Garcia wrote:
> Hi, I have been facing thread synchronization problems.
>
> I was trying to synchronize two threads using a binary semaphore to 
> protect critical parts of the code. Today I realized that the 
> semaphore was been acquired sequentially by both threads before It was 
> released by any of them. This behavior has been fixed when I have 
> disabled the cache memories, either the data cache or instruction 
> cache. Could you give me some hint about this??
>
> I'm using our own BSP for the zcu102, which was generated by modifying 
> the xilinx-zynq bsp for the RTEMS release 4.11.3. This behavior can be 
> related to a wrong implementation of the BSP?? 

Please run the smplock01 and smpatomic01 on your board. I guess the 
cache snooping is not enabled.

SMP is experimental in RTEMS 4.11. I would use the RTEMS master.

-- 
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.huber at embedded-brains.de
PGP     : Public key available on request.

Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.