[ltt-dev] [PATCH 3/5] rculfhash: use DEFAULT_SPLIT_COUNT_MASK for !HAVE_SYSCONF

[Mathieu Desnoyers]

* Lai Jiangshan (laijs at cn.fujitsu.com) wrote:
> Now, item accounting is always available.

Merged, thanks!

Mathieu

> 
> Signed-off-by: Lai Jiangshan <laijs at cn.fujitsu.com>
> ---
>  rculfhash.c |   60 +++++++++++++---------------------------------------------
>  1 files changed, 14 insertions(+), 46 deletions(-)
> 
> diff --git a/rculfhash.c b/rculfhash.c
> index ea6df05..5ea133f 100644
> --- a/rculfhash.c
> +++ b/rculfhash.c
> @@ -182,6 +182,7 @@
>   * tables and machines lacking per-cpu data suppport.
>   */
>  #define COUNT_COMMIT_ORDER		10
> +#define DEFAULT_SPLIT_COUNT_MASK	0xFUL
>  #define CHAIN_LEN_TARGET		1
>  #define CHAIN_LEN_RESIZE_THRESHOLD	3
>  
> @@ -500,14 +501,6 @@ int get_count_order_ulong(unsigned long x)
>  static
>  void cds_lfht_resize_lazy(struct cds_lfht *ht, unsigned long size, int growth);
>  
> -/*
> - * If the sched_getcpu() and sysconf(_SC_NPROCESSORS_CONF) calls are
> - * available, then we support hash table item accounting.
> - * In the unfortunate event the number of CPUs reported would be
> - * inaccurate, we use modulo arithmetic on the number of CPUs we got.
> - */
> -#if defined(HAVE_SYSCONF)
> -
>  static
>  void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size,
>  				unsigned long count);
> @@ -515,6 +508,7 @@ void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size,
>  static long nr_cpus_mask = -1;
>  static long split_count_mask = -1;
>  
> +#if defined(HAVE_SYSCONF)
>  static void ht_init_nr_cpus_mask(void)
>  {
>  	long maxcpus;
> @@ -531,6 +525,12 @@ static void ht_init_nr_cpus_mask(void)
>  	maxcpus = 1UL << get_count_order_ulong(maxcpus);
>  	nr_cpus_mask = maxcpus - 1;
>  }
> +#else /* #if defined(HAVE_SYSCONF) */
> +static void ht_init_nr_cpus_mask(void)
> +{
> +	nr_cpus_mask = -2;
> +}
> +#endif /* #else #if defined(HAVE_SYSCONF) */
>  
>  static
>  struct ht_items_count *alloc_split_items_count(void)
> @@ -539,13 +539,14 @@ struct ht_items_count *alloc_split_items_count(void)
>  
>  	if (nr_cpus_mask == -1)	{
>  		ht_init_nr_cpus_mask();
> -		split_count_mask = nr_cpus_mask;
> +		if (nr_cpus_mask < 0)
> +			split_count_mask = DEFAULT_SPLIT_COUNT_MASK;
> +		else
> +			split_count_mask = nr_cpus_mask;
>  	}
>  
> -	if (split_count_mask < 0)
> -		return NULL;
> -	else
> -		return calloc(split_count_mask + 1, sizeof(*count));
> +	assert(split_count_mask >= 0);
> +	return calloc(split_count_mask + 1, sizeof(*count));
>  }
>  
>  static
> @@ -635,35 +636,6 @@ void ht_count_del(struct cds_lfht *ht, unsigned long size, unsigned long hash)
>  	}
>  }
>  
> -#else /* #if defined(HAVE_SYSCONF) */
> -
> -static const long nr_cpus_mask = -2;
> -static const long split_count_mask = -2;
> -
> -static
> -struct ht_items_count *alloc_split_items_count(void)
> -{
> -	return NULL;
> -}
> -
> -static
> -void free_split_items_count(struct ht_items_count *count)
> -{
> -}
> -
> -static
> -void ht_count_add(struct cds_lfht *ht, unsigned long size, unsigned long hash)
> -{
> -}
> -
> -static
> -void ht_count_del(struct cds_lfht *ht, unsigned long size, unsigned long hash)
> -{
> -}
> -
> -#endif /* #else #if defined(HAVE_SYSCONF) */
> -
> -
>  static
>  void check_resize(struct cds_lfht *ht, unsigned long size, uint32_t chain_len)
>  {
> @@ -1815,8 +1787,6 @@ void cds_lfht_resize_lazy(struct cds_lfht *ht, unsigned long size, int growth)
>  	}
>  }
>  
> -#if defined(HAVE_SYSCONF)
> -
>  static
>  void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size,
>  				unsigned long count)
> @@ -1841,5 +1811,3 @@ void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size,
>  		CMM_STORE_SHARED(ht->t.resize_initiated, 1);
>  	}
>  }
> -
> -#endif
> -- 
> 1.7.4.4
> 

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com