From: Gavin Hu <gavin.hu@arm.com>
To: dev@dpdk.org
Cc: nd@arm.com, david.marchand@redhat.com, thomas@monjalon.net,
jerinj@marvell.com, xiaolong.ye@intel.com,
Honnappa.Nagarahalli@arm.com, ruifeng.wang@arm.com,
phil.yang@arm.com, joyce.kong@arm.com, steve.capper@arm.com,
stable@dpdk.org
Subject: [dpdk-stable] [PATCH v1 1/3] net/i40e: relax barrier in the Tx fastpath of vPMD
Date: Fri, 6 Mar 2020 13:04:25 +0800 [thread overview]
Message-ID: <20200306050427.66114-2-gavin.hu@arm.com> (raw)
In-Reply-To: <20200306050427.66114-1-gavin.hu@arm.com>
To keep ordering of mixed accesses, rte_cio is sufficient.
The rte_io barrier inside the I40E_PCI_REG_WRITE is overkill.[1]
This patch fixes by replacing with just sufficient barriers in the
normal PMD and vPMD.
It showed 7% performance uplift on ThunderX2 and 4% on Arm N1SDP.
The test case is the RFC2544 zero-loss test running testpmd.
[1] http://inbox.dpdk.org/dev/CALBAE1M-ezVWCjqCZDBw+MMDEC4O9
qf0Kpn89EMdGDajepKoZQ@mail.gmail.com
Fixes: 4861cde46116 ("i40e: new poll mode driver")
Cc: stable@dpdk.org
Signed-off-by: Gavin Hu <gavin.hu@arm.com>
---
drivers/net/i40e/i40e_rxtx_vec_neon.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/i40e/i40e_rxtx_vec_neon.c b/drivers/net/i40e/i40e_rxtx_vec_neon.c
index deb185fe2..4376d8911 100644
--- a/drivers/net/i40e/i40e_rxtx_vec_neon.c
+++ b/drivers/net/i40e/i40e_rxtx_vec_neon.c
@@ -72,8 +72,9 @@ i40e_rxq_rearm(struct i40e_rx_queue *rxq)
rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
(rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
+ rte_cio_wmb();
/* Update the tail pointer on the NIC */
- I40E_PCI_REG_WRITE(rxq->qrx_tail, rx_id);
+ I40E_PCI_REG_WRITE_RELAXED(rxq->qrx_tail, rx_id);
}
static inline void
@@ -564,7 +565,8 @@ i40e_xmit_fixed_burst_vec(void *tx_queue, struct rte_mbuf **tx_pkts,
txq->tx_tail = tx_id;
- I40E_PCI_REG_WRITE(txq->qtx_tail, txq->tx_tail);
+ rte_cio_wmb();
+ I40E_PCI_REG_WRITE_RELAXED(txq->qtx_tail, tx_id);
return nb_pkts;
}
--
2.17.1
next parent reply other threads:[~2020-03-06 5:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200413155640.53581-1-gavin.hu@arm.com>
[not found] ` <20200306050427.66114-1-gavin.hu@arm.com>
2020-03-06 5:04 ` Gavin Hu [this message]
2020-03-06 9:11 ` [dpdk-stable] [dpdk-dev] " Jerin Jacob
2020-04-13 15:56 ` [dpdk-stable] [PATCH v2 1/2] net/i40e: relax barrier in Tx fastpath for NEON vPMD Gavin Hu
2020-04-13 16:40 ` [dpdk-stable] [PATCH v3 " Gavin Hu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200306050427.66114-2-gavin.hu@arm.com \
--to=gavin.hu@arm.com \
--cc=Honnappa.Nagarahalli@arm.com \
--cc=david.marchand@redhat.com \
--cc=dev@dpdk.org \
--cc=jerinj@marvell.com \
--cc=joyce.kong@arm.com \
--cc=nd@arm.com \
--cc=phil.yang@arm.com \
--cc=ruifeng.wang@arm.com \
--cc=stable@dpdk.org \
--cc=steve.capper@arm.com \
--cc=thomas@monjalon.net \
--cc=xiaolong.ye@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).