Re: [Xenomai-core] XENO_OPT_SYS_STACKPOOLSZ vs. switchtest

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

Gilles Chanteperdrix wrote:
> Jan Kiszka wrote:
>> Gilles Chanteperdrix wrote:
>>> Jan Kiszka wrote:
>>>> Hi Gilles,
>>>>
>>>> how much XENO_OPT_SYS_STACKPOOLSZ do I need to run switchtest for
>>>> default settings? At least on x86-64, the default 32K is not enough.
>>>> Unless we talk about GB ;), maybe it makes sense to adjust the default
>>>> size accordingly.
>>> It depends on the arguments you pass to switchtest.
>> None, ie. the default settings.
> 
> Then 6 kernel-space tasks are created. Since switchtest is not the

6*4 is 20k... Ah, the well-known allocator overhead, I guess. Will try
with >= 40k.

> average use of Xenomai, and is supposed to be used only for validating
> the context/FPU switches, I would not change XENO_OPT_SYS_STACKPOOL_SZ,
> maybe only add a clear message when creation of kernel-space tasks fails.

Well, isn't the switchtest part of xeno-test? Would be unfortunate to
require a kernel rebuild just for running the standard tests. I think we
don't loose much by slightly increasing the stack to, say, 64K on 32 bit
and 128K on 64 bit archs.

BTW, XNARCH_THREAD_STACKSZ for x86-64 equals the x86-32 bit value (4K)
while I don't think the have they same demands (nor the same resource
restrictions).

Jan

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