Re: [PATCH 5/5] kern: make struct kmem_cache fit into two cache lines

[Samuel Thibault]

Justus Winter, le Thu 02 Jan 2014 20:02:46 +0100, a écrit :
> Previously, the size of struct kmem_cache was 136 bytes, just eight
> bytes larger than 128 bytes, which is typically two cache lines on
> today's CPUs.
> 
> By reducing the size of the name field which holds a human-readable
> description by eight bytes to 24 bytes, the struct kmem_cache can be
> made fit into two cache lines.  This change should not affect the
> usefulness of this field.  For reference, the length of the largest
> hard-coded name is 17.
> 
> * kern/slab.h (KMEM_CACHE_NAME_SIZE): Define to 24.

Ack.

> ---
>  kern/slab.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kern/slab.h b/kern/slab.h
> index b842fb7..a4219c4 100644
> --- a/kern/slab.h
> +++ b/kern/slab.h
> @@ -149,7 +149,7 @@ typedef void (*kmem_slab_free_fn_t)(vm_offset_t, 
> vm_size_t);
>  /*
>   * Cache name buffer size.
>   */
> -#define KMEM_CACHE_NAME_SIZE 32
> +#define KMEM_CACHE_NAME_SIZE 24
>  
>  /*
>   * Cache of objects.
> -- 
> 1.8.5.2
> 

-- 
Samuel
AUTHOR
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