Subject: Re: [PATCH 1/2] [CRYPTO] tcrypt: Move sg_init_table out of timing loops

From: Boaz Harrosh <[email-masked]>
Date: Tue, 30 Oct 2007 11:31:45 +0200

On Mon, Oct 29 2007 at 22:16 +0200, Jens Axboe <[email-masked]> wrote:
> On Fri, Oct 26 2007, Herbert Xu wrote:
>> [CRYPTO] tcrypt: Move sg_init_table out of timing loops
>>
>> This patch moves the sg_init_table out of the timing loops for hash
>> algorithms so that it doesn't impact on the speed test results.
> 
> Wouldn't it be better to just make sg_init_one() call sg_init_table?
> 
> diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
> index 4571231..ccc55a6 100644
> --- a/include/linux/scatterlist.h
> +++ b/include/linux/scatterlist.h
> @@ -202,28 +202,6 @@ static inline void __sg_mark_end(struct scatterlist *sg)
>  }
>  
>  /**
> - * sg_init_one - Initialize a single entry sg list
> - * @sg:		 SG entry
> - * @buf:	 Virtual address for IO
> - * @buflen:	 IO length
> - *
> - * Notes:
> - *   This should not be used on a single entry that is part of a larger
> - *   table. Use sg_init_table() for that.
> - *
> - **/
> -static inline void sg_init_one(struct scatterlist *sg, const void *buf,
> -			       unsigned int buflen)
> -{
> -	memset(sg, 0, sizeof(*sg));
> -#ifdef CONFIG_DEBUG_SG
> -	sg->sg_magic = SG_MAGIC;
> -#endif
> -	sg_mark_end(sg, 1);
> -	sg_set_buf(sg, buf, buflen);
> -}
> -
> -/**
>   * sg_init_table - Initialize SG table
>   * @sgl:	   The SG table
>   * @nents:	   Number of entries in table
> @@ -247,6 +225,24 @@ static inline void sg_init_table(struct scatterlist *sgl, unsigned int nents)
>  }
>  
>  /**
> + * sg_init_one - Initialize a single entry sg list
> + * @sg:		 SG entry
> + * @buf:	 Virtual address for IO
> + * @buflen:	 IO length
> + *
> + * Notes:
> + *   This should not be used on a single entry that is part of a larger
> + *   table. Use sg_init_table() for that.
> + *
> + **/
> +static inline void sg_init_one(struct scatterlist *sg, const void *buf,
> +			       unsigned int buflen)
> +{
> +	sg_init_table(sg, 1);
> +	sg_set_buf(sg, buf, buflen);
> +}
> +
> +/**
>   * sg_phys - Return physical address of an sg entry
>   * @sg:	     SG entry
>   *
> 
Yes please submit this patch. scsi-ml is full of sg_init_one, specially
on the error recovery path.

Thanks
Boaz