Re: Patch - Add pthread affinity for RTEMS

[Sebastian Huber <sebastian dot huber at embedded-brains dot de>]

On 2013-11-22 15:30, Joel Sherrill wrote:
> Hi
>
> This patch follows up on the recent addition of the
> RTEMS specific cpuset.h and adds GNU/Linux style
> pthread affinity APIs to pthread.h.
>
> Sebastian.. we think the guards follow your recommendations.
>
> OK to commit?
>
> 2013-11-22  Jennifer Averett<jennifer.averett@oarcorp.com>
>
>          * libc/include/pthread.h (pthread_attr_setaffinity_np,
>          pthread_attr_getaffinity_np, pthread_setaffinity_np,
>          pthread_getaffinity_np, pthread_getattr_np): Add pthread obtain
>          attribute and SMP affinity methods to RTEMS for compatibility
>          with GNU/Linux.
>          * libc/include/sys/types.h: Add cpuset to pthread_attr_t for RTEMS.
>
> -- Joel Sherrill, Ph.D. Director of Research & Development
> joel.sherrill@OARcorp.com On-Line Applications Research Ask me about RTEMS: a
> free RTOS Huntsville AL 35805 Support Available (256) 722-9985
>
>
> pthread-affinity.diff
>
>
> ? newlib/libc/include/sys/.types.h.swp
> ? newlib/libc/sys/rtems/sys/cpuset.h
> Index: newlib/libc/include/pthread.h
> ===================================================================
> RCS file: /cvs/src/src/newlib/libc/include/pthread.h,v
> retrieving revision 1.10
> diff -u -r1.10 pthread.h
> --- newlib/libc/include/pthread.h	22 Jan 2013 21:20:08 -0000	1.10
> +++ newlib/libc/include/pthread.h	11 Nov 2013 19:51:02 -0000
> @@ -2,7 +2,7 @@
>    *
>    *  Written by Joel Sherrill<joel@OARcorp.com>.
>    *
> - *  COPYRIGHT (c) 1989-2010.
> + *  COPYRIGHT (c) 1989-2013.
>    *  On-Line Applications Research Corporation (OAR).
>    *
>    *  Permission to use, copy, modify, and distribute this software for any
> @@ -206,6 +206,24 @@
>   int	_EXFUN(pthread_attr_setguardsize,
>   	(pthread_attr_t *__attr, size_t __guardsize));
>
> +#if defined(__USE_GNU) && defined(__rtems__)

I would rather use

#ifdef _GNU_SOURCE

> +/* POSIX thread APIs beyond the POSIX standard but provided in RTEMS
> + * for compatibility with GNU/Linux.
> + */
> +int	_EXFUN(pthread_attr_setaffinity_np,
> +	(pthread_attr_t *__attr,size_t __cpusetsize,
> +	const cpu_set_t *__cpuset));
> +int 	_EXFUN(pthread_attr_getaffinity_np,
> +	(const pthread_attr_t *__attr, size_t __cpusetsize,
> +	cpu_set_t *__cpuset));
> +int	_EXFUN(pthread_getattr_np,
> +	(pthread_t __thread, pthread_attr_t *__attr));
> +int	_EXFUN(pthread_setaffinity_np,
> +	(pthread_t __id, size_t __cpusetsize, const cpu_set_t *__cpuset));
> +int	_EXFUN(pthread_getaffinity_np,
> +	(const pthread_t __id, size_t __cpusetsize, cpu_set_t *__cpuset));
> +#endif
> +
>   /* Thread Creation, P1003.1c/Draft 10, p. 144 */
>
>   int	_EXFUN(pthread_create,
> Index: newlib/libc/include/sys/types.h
> ===================================================================
> RCS file: /cvs/src/src/newlib/libc/include/sys/types.h,v
> retrieving revision 1.40
> diff -u -r1.40 types.h
> --- newlib/libc/include/sys/types.h	5 Jul 2013 21:46:10 -0000	1.40
> +++ newlib/libc/include/sys/types.h	11 Nov 2013 19:51:02 -0000
> @@ -322,6 +322,10 @@
>   #define PTHREAD_CREATE_DETACHED 0
>   #define PTHREAD_CREATE_JOINABLE  1
>
> +#if defined(__rtems__)
> +  #include <sys/cpuset.h>
> +#endif
> +
>   #if defined(__XMK__)
>   typedef struct pthread_attr_s {
>     int contentionscope;
> @@ -342,16 +346,16 @@
>     int inheritsched;
>     int schedpolicy;
>     struct sched_param schedparam;
> -#if defined(__rtems__)
> -  size_t guardsize;
> -#endif
>
>     /* P1003.4b/D8, p. 54 adds cputime_clock_allowed attribute.  */
>   #if defined(_POSIX_THREAD_CPUTIME)
>     int  cputime_clock_allowed;  /* see time.h */
>   #endif
>     int  detachstate;
> -
> +#if defined(__rtems__)
> +  size_t guardsize;
> +  cpu_set_t affinity;

In the pthread_attr_setaffinity_np() function we allow arbitrary sized CPU 
sets.  What happens if sizeof(cpu_set_t) < __cpusetsize?

> +#endif
>   } pthread_attr_t;
>
>   #endif /* !defined(__XMK__) */


--
Sebastian Huber, embedded brains GmbH

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