From: Feifei Wang <feifei.wang2@arm.com>
To: Ruifeng Wang <ruifeng.wang@arm.com>, Beilei Xing <beilei.xing@intel.com>
Cc: dev@dpdk.org, nd@arm.com, Feifei Wang <feifei.wang2@arm.com>
Subject: [dpdk-dev] [PATCH v1 4/4] net/i40e: change code order to reduce L1 cache misses
Date: Fri, 23 Jul 2021 11:10:49 +0800 [thread overview]
Message-ID: <20210723031049.2201665-5-feifei.wang2@arm.com> (raw)
In-Reply-To: <20210723031049.2201665-1-feifei.wang2@arm.com>
For N1 platform, packet mbuf load and descs load are hot spots to limit
the performance for "desc_to_ptype_v" and "desc_to_olflags_v" functions
in i40e rx NEON path. This is because packet mbuf and descs are evicted
from l1d-cache to l2d-cache.
To reduce l1d-cache-misses and improve the performance, change the code
order and move "desc_to_ptype_v" and "desc_to_olflags_v" functions
forward to the location, where packet mbuf and descs are just loaded.
Test Result:
dpdk:21.08-rc1
gcc-9
For n1sdp, the patch improves the performance by 1.8%.
For thunderx2, no performance changes.
Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
---
drivers/net/i40e/i40e_rxtx_vec_neon.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/drivers/net/i40e/i40e_rxtx_vec_neon.c b/drivers/net/i40e/i40e_rxtx_vec_neon.c
index 8f3188e910..b2683fda60 100644
--- a/drivers/net/i40e/i40e_rxtx_vec_neon.c
+++ b/drivers/net/i40e/i40e_rxtx_vec_neon.c
@@ -301,18 +301,6 @@ _recv_raw_pkts_vec(struct i40e_rx_queue *__rte_restrict rxq,
rte_mbuf_prefetch_part2(rx_pkts[pos + 3]);
}
- /* C.1 4=>2 filter staterr info only */
- sterr_tmp2 = vzipq_u16(vreinterpretq_u16_u64(descs[1]),
- vreinterpretq_u16_u64(descs[3]));
- sterr_tmp1 = vzipq_u16(vreinterpretq_u16_u64(descs[0]),
- vreinterpretq_u16_u64(descs[2]));
-
- /* C.2 get 4 pkts staterr value */
- staterr = vzipq_u16(sterr_tmp1.val[1],
- sterr_tmp2.val[1]).val[0];
-
- desc_to_olflags_v(rxq, descs, &rx_pkts[pos]);
-
/* pkts shift the pktlen field to be 16-bit aligned*/
uint32x4_t len3 = vshlq_u32(vreinterpretq_u32_u64(descs[3]),
len_shl);
@@ -367,10 +355,22 @@ _recv_raw_pkts_vec(struct i40e_rx_queue *__rte_restrict rxq,
desc_to_ptype_v(descs, &rx_pkts[pos], ptype_tbl);
+ desc_to_olflags_v(rxq, descs, &rx_pkts[pos]);
+
if (likely(pos + RTE_I40E_DESCS_PER_LOOP < nb_pkts)) {
rte_prefetch_non_temporal(rxdp + RTE_I40E_DESCS_PER_LOOP);
}
+ /* C.1 4=>2 filter staterr info only */
+ sterr_tmp2 = vzipq_u16(vreinterpretq_u16_u64(descs[1]),
+ vreinterpretq_u16_u64(descs[3]));
+ sterr_tmp1 = vzipq_u16(vreinterpretq_u16_u64(descs[0]),
+ vreinterpretq_u16_u64(descs[2]));
+
+ /* C.2 get 4 pkts staterr value */
+ staterr = vzipq_u16(sterr_tmp1.val[1],
+ sterr_tmp2.val[1]).val[0];
+
/* C* extract and record EOP bit */
if (split_packet) {
uint8x16_t eop_shuf_mask = {
--
2.25.1
next prev parent reply other threads:[~2021-07-23 3:11 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-23 3:10 [dpdk-dev] [PATCH v1 0/4] fix note error Feifei Wang
2021-07-23 3:10 ` [dpdk-dev] [PATCH v1 1/4] drivers/net: remove redundant phrases Feifei Wang
2021-07-23 3:10 ` [dpdk-dev] [PATCH v1 2/4] drivers/net: fix note error for Rx vector Feifei Wang
2021-07-23 3:10 ` [dpdk-dev] [PATCH v1 3/4] net/i40e: reorder Rx NEON code for better readability Feifei Wang
2021-07-23 3:10 ` Feifei Wang [this message]
2021-08-10 3:00 ` [dpdk-dev] [PATCH v1 0/4] fix note error Zhang, Qi Z
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