From: Stephen Hemminger <stephen@networkplumber.org>
To: huawei.xie@intel.com, changchun.ouyang@intel.com
Cc: dev@dpdk.org
Subject: [dpdk-dev] [PATCH 2/5] virtio: don't use unlikely for normal tx stuff
Date: Sun, 18 Oct 2015 22:16:09 -0700 [thread overview]
Message-ID: <1445231772-17467-3-git-send-email-stephen@networkplumber.org> (raw)
In-Reply-To: <1445231772-17467-1-git-send-email-stephen@networkplumber.org>
Don't use unlikely() for VLAN or ring getting full.
GCC will not optimize code in unlikely paths and since these can
happen with normal code that can hurt performance.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
drivers/net/virtio/virtio_rxtx.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index 5b50ed0..dbe6665 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -763,7 +763,7 @@ virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
int need = txm->nb_segs - txvq->vq_free_cnt + 1;
/* Positive value indicates it need free vring descriptors */
- if (unlikely(need > 0)) {
+ if (need > 0) {
nb_used = VIRTQUEUE_NUSED(txvq);
virtio_rmb();
need = RTE_MIN(need, (int)nb_used);
@@ -778,7 +778,7 @@ virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
}
/* Do VLAN tag insertion */
- if (unlikely(txm->ol_flags & PKT_TX_VLAN_PKT)) {
+ if (txm->ol_flags & PKT_TX_VLAN_PKT) {
error = rte_vlan_insert(&txm);
if (unlikely(error)) {
rte_pktmbuf_free(txm);
@@ -798,10 +798,9 @@ virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
break;
}
txvq->bytes += txm->pkt_len;
+ ++txvq->packets;
}
- txvq->packets += nb_tx;
-
if (likely(nb_tx)) {
vq_update_avail_idx(txvq);
--
2.1.4
next prev parent reply other threads:[~2015-10-19 5:16 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-19 5:16 [dpdk-dev] [PATCH v2 0/5] virtio: Tx performance improvements Stephen Hemminger
2015-10-19 5:16 ` [dpdk-dev] [PATCH 1/5] virtio: clean up space checks on xmit Stephen Hemminger
2015-10-19 8:02 ` Xie, Huawei
2015-10-19 15:48 ` Stephen Hemminger
2015-10-19 16:27 ` Xie, Huawei
2015-10-19 5:16 ` Stephen Hemminger [this message]
2015-10-19 5:16 ` [dpdk-dev] [PATCH 3/5] virtio: use indirect ring elements Stephen Hemminger
2015-10-19 13:19 ` Xie, Huawei
2015-10-19 15:47 ` Stephen Hemminger
2015-10-19 16:18 ` Xie, Huawei
2015-10-30 18:01 ` Thomas Monjalon
2015-10-19 5:16 ` [dpdk-dev] [PATCH 4/5] virtio: use any layout on transmit Stephen Hemminger
2015-10-19 16:28 ` Xie, Huawei
2015-10-19 16:43 ` Stephen Hemminger
2015-10-19 16:56 ` Xie, Huawei
2015-10-26 23:47 ` Stephen Hemminger
2015-10-19 17:19 ` Stephen Hemminger
2015-10-19 5:16 ` [dpdk-dev] [PATCH 5/5] virtio: optimize transmit enqueue Stephen Hemminger
2015-10-20 1:48 ` Xie, Huawei
2015-10-21 13:18 ` [dpdk-dev] [PATCH v2 0/5] virtio: Tx performance improvements Thomas Monjalon
2015-10-22 10:38 ` Xie, Huawei
2015-10-22 12:13 ` Xie, Huawei
2015-10-22 16:04 ` Stephen Hemminger
2015-10-23 9:00 ` Xie, Huawei
2015-10-26 23:52 ` Stephen Hemminger
2015-10-27 1:56 ` Xie, Huawei
2015-10-27 2:23 ` Stephen Hemminger
2015-10-27 2:38 ` Xie, Huawei
2015-10-26 14:05 ` Xie, Huawei
2016-01-05 8:10 ` Xie, Huawei
2016-01-06 12:03 ` Thomas Monjalon
2016-01-14 13:49 ` Xie, Huawei
2016-03-04 6:18 ` Xie, Huawei
2016-03-04 18:17 ` Stephen Hemminger
2016-03-08 1:38 ` Xie, Huawei
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