[PATCH 4/4] score: Use Resource Handler for MrsP semaphores

Sebastian Huber sebastian.huber at embedded-brains.de
Tue Jun 3 10:55:25 UTC 2014


On 2014-06-02 15:32, Joel Sherrill wrote:
>
> On Jun 2, 2014 9:28 AM, Sebastian Huber <sebastian.huber at embedded-brains.de> wrote:
>  >
>  > On 2014-06-02 15:24, Joel Sherrill wrote:
>  > > Does this resource tracking replace the code for strict order mutex?
>  >
>  > No, the MrsP (and maybe later the Migratory Priority Inheritance) semaphores
>  > are completely separate.
>  >
>  > In theory it is possible to use it also for the uni-processor semaphores, but I
>  > am not sure if its worth to add this overhead.  The implementation with the
>  > resource count is analytically not correct, but very efficient.  Was this
>  > really a source for trouble in the last 20 years or so?
>
> Not from a performance viewpoint but from a system end to end priority
> analysis, it is less than ideal.
>

I think the bigger problem is that the priority inheritance affects only one 
level, see new test sptests/spsem03.

-- 
Sebastian Huber, embedded brains GmbH

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