Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b3226184 authored by Roland Dreier's avatar Roland Dreier
Browse files

IB/mlx4: Micro-optimize mlx4_ib_poll_one() 



Rather than byte-swapping cqe->g_mlpath_rqpn each time we extract a
field from it, byte-swap it once into a temporary variable.  This 
results in smaller, better code -- eg, on 32-bit x86:

add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-5 (-5)
function                                     old     new   delta
mlx4_ib_poll_cq                             1188    1183      -5

Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
parent e57895d3

drivers/infiniband/hw/mlx4/cq.c

+5 −4
Original line number Diff line number Diff line
@@ -313,6 +313,7 @@ static int mlx4_ib_poll_one(struct mlx4_ib_cq *cq, 
	struct mlx4_ib_srq *srq;

	int is_send;

	int is_error;

	u32 g_mlpath_rqpn;

	u16 wqe_ctr;



	cqe = next_cqe_sw(cq);
@@ -426,10 +427,10 @@ static int mlx4_ib_poll_one(struct mlx4_ib_cq *cq, 


		wc->slid	   = be16_to_cpu(cqe->rlid);

		wc->sl		   = cqe->sl >> 4;

		wc->src_qp	   = be32_to_cpu(cqe->g_mlpath_rqpn) & 0xffffff;

		wc->dlid_path_bits = (be32_to_cpu(cqe->g_mlpath_rqpn) >> 24) & 0x7f;

		wc->wc_flags      |= be32_to_cpu(cqe->g_mlpath_rqpn) & 0x80000000 ?

			IB_WC_GRH : 0;

		g_mlpath_rqpn	   = be32_to_cpu(cqe->g_mlpath_rqpn);

		wc->src_qp	   = g_mlpath_rqpn & 0xffffff;

		wc->dlid_path_bits = (g_mlpath_rqpn >> 24) & 0x7f;

		wc->wc_flags	  |= g_mlpath_rqpn & 0x80000000 ? IB_WC_GRH : 0;

		wc->pkey_index     = be32_to_cpu(cqe->immed_rss_invalid) & 0x7f;

	}