Subject: Re: [PATCH for-next 03/11] IB/hns: Optimize the logic of allocating memory using APIs

From: Leon Romanovsky <[email-masked]>
Date: Wed, 9 Nov 2016 09:21:30 +0200

On Fri, Nov 04, 2016 at 04:36:25PM +0000, Salil Mehta wrote:
> From: "Wei Hu (Xavier)" <[email-masked]>
>
> This patch modified the logic of allocating memory using APIs in
> hns RoCE driver. We used kcalloc instead of kmalloc_array and
> bitmap_zero. And When kcalloc failed, call vzalloc to alloc
> memory.
>
> Signed-off-by: Wei Hu (Xavier) <[email-masked]>
> Signed-off-by: Ping Zhang <[email-masked]>
> Signed-off-by: Salil Mehta  <[email-masked]>
> ---
>  drivers/infiniband/hw/hns/hns_roce_mr.c |   15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/infiniband/hw/hns/hns_roce_mr.c b/drivers/infiniband/hw/hns/hns_roce_mr.c
> index fb87883..d3dfb5f 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_mr.c
> +++ b/drivers/infiniband/hw/hns/hns_roce_mr.c
> @@ -137,11 +137,12 @@ static int hns_roce_buddy_init(struct hns_roce_buddy *buddy, int max_order)
>
>  	for (i = 0; i <= buddy->max_order; ++i) {
>  		s = BITS_TO_LONGS(1 << (buddy->max_order - i));
> -		buddy->bits[i] = kmalloc_array(s, sizeof(long), GFP_KERNEL);
> -		if (!buddy->bits[i])
> -			goto err_out_free;
> -
> -		bitmap_zero(buddy->bits[i], 1 << (buddy->max_order - i));
> +		buddy->bits[i] = kcalloc(s, sizeof(long), GFP_KERNEL);
> +		if (!buddy->bits[i]) {
> +			buddy->bits[i] = vzalloc(s * sizeof(long));

I wonder, why don't you use directly vzalloc instead of kcalloc fallback?

> +			if (!buddy->bits[i])
> +				goto err_out_free;
> +		}
>  	}