Re: [Xenomai-help] heap allocation in xenomai

[Jan Kiszka <jan.kiszka@domain.hid>]

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manoj kumar wrote:
> Hi,
> 
> Could anybody tell me about heap allocation in xenomai by API
> rt_heap_create().
> 
> Why heap creation is required? Please tell the uses in detail?

The native skin's heaps provide means to reserve separate memory pools
and to perform deterministic allocation on it (as far as the heap usage
patterns are known).

For further derails, please read the API documentation and consult e.g.
the demo code: ksrc/skins/native/snippets/local_heap.c. Or ask a bit
more concrete questions.

> 
> Can kmalloc & free be used in any RT program at kernel space? If yes, Are
> there any limitation on that? if Yes, then which are those.

You can, but only during module init/cleanup, *NOT* while running inside
an RT task. That's because these Linux services may have been preempted
by Xenomai at any point while Linux was using it, and a re-entrance from
a Xenomai task would corrupt them.

Jan


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