IB/mlx4: Micro-optimize mlx4_ib_post_send()

Rather than have build_mlx_header() return a negative value on failure
and the length of the segments it builds on success, add a pointer
parameter to return the length and return 0 on success.  This matches
the calling convention used for build_lso_seg() and generates slightly
smaller code -- eg, on 64-bit x86:

add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-22 (-22)
function                                     old     new   delta
mlx4_ib_post_send                           2023    2001     -22

Signed-off-by: Roland Dreier <rolandd@cisco.com>
This commit is contained in:
Roland Dreier 2008-04-16 21:09:28 -07:00
parent b832be1e40
commit f438000f7a

View File

@ -1200,7 +1200,7 @@ out:
}
static int build_mlx_header(struct mlx4_ib_sqp *sqp, struct ib_send_wr *wr,
void *wqe)
void *wqe, unsigned *mlx_seg_len)
{
struct ib_device *ib_dev = &to_mdev(sqp->qp.ibqp.device)->ib_dev;
struct mlx4_wqe_mlx_seg *mlx = wqe;
@ -1321,7 +1321,9 @@ static int build_mlx_header(struct mlx4_ib_sqp *sqp, struct ib_send_wr *wr,
i = 2;
}
return ALIGN(i * sizeof (struct mlx4_wqe_inline_seg) + header_size, 16);
*mlx_seg_len =
ALIGN(i * sizeof (struct mlx4_wqe_inline_seg) + header_size, 16);
return 0;
}
static int mlx4_wq_overflow(struct mlx4_ib_wq *wq, int nreq, struct ib_cq *ib_cq)
@ -1548,15 +1550,13 @@ int mlx4_ib_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
case IB_QPT_SMI:
case IB_QPT_GSI:
err = build_mlx_header(to_msqp(qp), wr, ctrl);
if (err < 0) {
err = build_mlx_header(to_msqp(qp), wr, ctrl, &seglen);
if (unlikely(err)) {
*bad_wr = wr;
goto out;
}
wqe += err;
size += err / 16;
err = 0;
wqe += seglen;
size += seglen / 16;
break;
default: