Re: [Xen-devel] [PATCH] block: replace kmalloc and then memcpy with kmemdup

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

On Mon, Mar 11, 2013 at 01:23:36PM +0200, Mihnea Dobrescu-Balaur wrote:

Are there performance improvements to doing it this way?

> Signed-off-by: Mihnea Dobrescu-Balaur <mihneadb@xxxxxxxxx>
> ---
>  drivers/block/xen-blkfront.c |    3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
> index c3dae2e..9620644 100644
> --- a/drivers/block/xen-blkfront.c
> +++ b/drivers/block/xen-blkfront.c
> @@ -1203,11 +1203,10 @@ static int blkif_recover(struct blkfront_info *info)
>       int j;
>  
>       /* Stage 1: Make a safe copy of the shadow state. */
> -     copy = kmalloc(sizeof(info->shadow),
> +     copy = kmemdup(info->shadow, sizeof(info->shadow),
>                      GFP_NOIO | __GFP_REPEAT | __GFP_HIGH);
>       if (!copy)
>               return -ENOMEM;
> -     memcpy(copy, info->shadow, sizeof(info->shadow));
>  
>       /* Stage 2: Set up free list. */
>       memset(&info->shadow, 0, sizeof(info->shadow));
> -- 
> 1.7.10.4
> 

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