Re: [Xenomai] [Xenomai-git] Jan Kiszka : cobalt/kernel: Allow to restart clock_nanosleep and select after signal processing

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

On Fri, May 27, 2016 at 08:36:43AM +0200, git repository hosting wrote:
> diff --git a/kernel/cobalt/include/asm-generic/xenomai/wrappers.h b/kernel/cobalt/include/asm-generic/xenomai/wrappers.h
> index 060ce85..0f9ab14 100644
> --- a/kernel/cobalt/include/asm-generic/xenomai/wrappers.h
> +++ b/kernel/cobalt/include/asm-generic/xenomai/wrappers.h
> @@ -133,4 +133,10 @@ devm_hwmon_device_register_with_groups(struct device *dev, const char *name,
>  #error "Xenomai/cobalt requires Linux kernel 3.10 or above"
>  #endif /* < 3.10 */
>  
> +#if LINUX_VERSION_CODE < KERNEL_VERSION(4,0,0)
> +#define cobalt_get_restart_block(p)	(&task_thread_info(p)->restart_block)
> +#else
> +#define cobalt_get_restart_block(p)	(&(p)->restart_block)
> +#endif
> +

This is bad. First off as explained in the comment heading
wrappers.h the wrappers are ordered by kernel version and the most
recent is first. Second, no other wrapper has a #else clause, the
idea is that we want to be able to remove some old wrappers from
time to time, and removing the #if completely should be enough.
Obviously, if you put a #else, this does not work. I agree that in
that case it is going to be hard, but please try anyway...

Other than that, I see your patch modifies each syscall handler
directly, can not the result be achieved in a different way? For
instance by factoring it in the core? Relying more on Linux syscall
restart mechanism.

-- 
					    Gilles.
https://click-hack.org