[ewg] [PATCH] ipoib_ud_skb_put optimization patch

[Or Gerlitz]

On 2/12/08, Shirley Ma <mashirle at us.ibm.com> wrote:

Hello, where is the change-log comment that explains what the patch is
doing? is it relevant to 2.6.25-rc1? if yes, please send it to the
general list for review.

> Signed-off-by: Shirley Ma <xma at us.ibm.com>
> ---
>
> diff -urpN ofed/drivers/infiniband/ulp/ipoib/ipoib_ib.c ofed_a/drivers/infiniband/ulp/ipoib/ipoib_ib.c
> --- ofed/drivers/infiniband/ulp/ipoib/ipoib_ib.c        2008-02-12 10:53:00.000000000 -0800
> +++ ofed_a/drivers/infiniband/ulp/ipoib/ipoib_ib.c      2008-02-12 11:04:54.000000000 -0800
> @@ -107,22 +107,17 @@ static void clean_pending_receives(struc
>  static void ipoib_ud_skb_put_frags(struct ipoib_dev_priv *priv, struct sk_buff *skb,
>                                    unsigned int length)
>  {
> -       if (ipoib_ud_need_sg(priv->max_ib_mtu)) {
> -               unsigned int size;
> -               skb_frag_t *frag = &skb_shinfo(skb)->frags[0];
> -
> -               /* put header into skb */
> -               size = min(length, (unsigned)IPOIB_UD_HEAD_SIZE);
> -               skb->tail += size;
> -               skb->len += size;
> -               length -= size;
> -
> -               size = min(length, (unsigned) PAGE_SIZE);
> -               frag->size = size;
> -               skb->data_len += size;
> -               skb->truesize += size;
> -               skb->len += size;
> -               length -= size;
> +       skb_frag_t *frag = &skb_shinfo(skb)->frags[0];
> +       if (skb_shinfo(skb)->nr_frags) {
> +               /*
> +                * we know only two buffers here, first buf size is
> +                * IPOIB_UD_HEAD_SIZE
> +                */
> +               skb->tail += IPOIB_UD_HEAD_SIZE;
> +               frag->size = length - IPOIB_UD_HEAD_SIZE;
> +               skb->data_len += frag->size;
> +               skb->truesize += frag->size;
> +               skb->len += length;
>         } else
>                 skb_put(skb, length);
>  }