Re: [Xenomai-help] fpu issue

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

Steven Seeger wrote:
> In pod.c:
> 
> __xnpod_init_fpu() is not called ever. However, init_fpu is called once
> in i387.c

__xnpod_init_fpu is for kernel-space thread. For user-space threads, the
FPU initialization happens either in Linux code if the fault happens in
secondary mode, or in the fault handler if it happens in primary mode.

> 
> After the program runs, __xnpod_giveup_fpu is called twice (remember, I
> have two threads)
> 
> __xnpod_release_fpu() never called
> 
> I can't put a printk in __xnpod_switch_fpu() because it freezes
> (continues to print forever)

Which is why I suggested printing only if !strcmp(current->comm,
"double_test"), and why you should stop double_test as soon as you
detect an error. Furthermore, what interest me is what branches are
taken in the various ifs found in xnarch_save_fpu, xnarch_restore_fpu,
xnarch_enable_fpu.

-- 
                                                 Gilles.