Counter API

Alexandre Martins alexandre.martins at stormshield.eu
Fri Feb 3 13:02:25 UTC 2017


Hi Kontantin.

Your patch compille and run great in a 32 bit environment. I don't have a 64 
bit one to check.

Thank you for your support.

Best regards

Alexandre

Le jeudi 2 février 2017, 18:01:59 Konstantin Belousov a écrit :
> On Thu, Feb 02, 2017 at 04:38:08PM +0100, Alexandre Martins wrote:
> > Hi all,
> > 
> > Our companie is curently tracking performance issue with our ARM product.
> > 
> > We have seen that counter API was migrated from intrinsic to atomic.
> > 
> > https://svnweb.freebsd.org/base?view=revision&revision=269406
> > 
> > But there is still the calls to critical_enter/leave in the macro
> > counter_enter/leave.
> > 
> > Is that needed ? Can we remove that ?
> 
> Try this.  I did not even compiled the patch.
> 
> diff --git a/sys/arm/include/counter.h b/sys/arm/include/counter.h
> index c4da91f7a14..950516e1616 100644
> --- a/sys/arm/include/counter.h
> +++ b/sys/arm/include/counter.h
> @@ -31,12 +31,9 @@
> 
>  #include <sys/pcpu.h>
>  #include <machine/atomic.h>
> -#ifdef INVARIANTS
> -#include <sys/proc.h>
> -#endif
> 
> -#define	counter_enter()	critical_enter()
> -#define	counter_exit()	critical_exit()
> +#define	counter_enter()	do {} while (0)
> +#define	counter_exit()	do {} while (0)
> 
>  #ifdef IN_SUBR_COUNTER_C
> 
> @@ -55,7 +52,7 @@ counter_u64_fetch_inline(uint64_t *p)
>  	int i;
> 
>  	r = 0;
> -	for (i = 0; i < mp_ncpus; i++)
> +	CPU_FOREACH(i)
>  		r += counter_u64_read_one((uint64_t *)p, i);
> 
>  	return (r);
> @@ -78,18 +75,13 @@ counter_u64_zero_inline(counter_u64_t c)
>  }
>  #endif
> 
> -#define	counter_u64_add_protected(c, inc)	do {	\
> -	CRITICAL_ASSERT(curthread);			\
> -	atomic_add_64((uint64_t *)zpcpu_get(c), (inc));	\
> -} while (0)
> +#define	counter_u64_add_protected(c, inc)	counter_u64_add(c, inc)
> 
>  static inline void
>  counter_u64_add(counter_u64_t c, int64_t inc)
>  {
> 
> -	counter_enter();
> -	counter_u64_add_protected(c, inc);
> -	counter_exit();
> +	atomic_add_64((uint64_t *)zpcpu_get(c), inc);
>  }
> 
>  #endif	/* ! __MACHINE_COUNTER_H__ */
> diff --git a/sys/arm64/include/counter.h b/sys/arm64/include/counter.h
> index 9d56cce3d3d..cfa521f9b73 100644
> --- a/sys/arm64/include/counter.h
> +++ b/sys/arm64/include/counter.h
> @@ -30,12 +30,10 @@
>  #define	_MACHINE_COUNTER_H_
> 
>  #include <sys/pcpu.h>
> -#ifdef INVARIANTS
> -#include <sys/proc.h>
> -#endif
> +#include <machine/atomic.h>
> 
> -#define	counter_enter()	critical_enter()
> -#define	counter_exit()	critical_exit()
> +#define	counter_enter()	do {} while (0)
> +#define	counter_exit()	do {} while (0)
> 
>  #ifdef IN_SUBR_COUNTER_C
>  static inline uint64_t
> @@ -52,13 +50,12 @@ counter_u64_fetch_inline(uint64_t *p)
>  	int i;
> 
>  	r = 0;
> -	for (i = 0; i < mp_ncpus; i++)
> +	CPU_FOREACH(i)
>  		r += counter_u64_read_one((uint64_t *)p, i);
> 
>  	return (r);
>  }
> 
> -/* XXXKIB might interrupt increment */
>  static void
>  counter_u64_zero_one_cpu(void *arg)
>  {
> @@ -76,18 +73,13 @@ counter_u64_zero_inline(counter_u64_t c)
>  }
>  #endif
> 
> -#define	counter_u64_add_protected(c, inc)	do {	\
> -	CRITICAL_ASSERT(curthread);			\
> -	*(uint64_t *)zpcpu_get(c) += (inc);		\
> -} while (0)
> +#define	counter_u64_add_protected(c, inc)	counter_u64_add(c, inc)
> 
>  static inline void
>  counter_u64_add(counter_u64_t c, int64_t inc)
>  {
> 
> -	counter_enter();
> -	counter_u64_add_protected(c, inc);
> -	counter_exit();
> +	atomic_add_64((uint64_t *)zpcpu_get(c), inc);
>  }
> 
>  #endif	/* ! _MACHINE_COUNTER_H_ */

-- 
Alexandre Martins
STORMSHIELD

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