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-dev] [PATCH v4] net/i40e: relaxed barrier in the tx fastpath
Date: Wed, 12 Feb 2020 13:56:21 +0800 [thread overview]
Message-ID: <20200212055621.118363-1-gavin.hu@arm.com> (raw)
In-Reply-To: <1571758074-16445-1-git-send-email-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]
[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>
---
V4:
- add the Fixes tag and CC stable <Xiaolong Ye>
V3:
- optimize the barriers in the fast path only, leave as it is for the
barriers in the slow path and control path <jerin>
- drop the virtio patches from the list as they are in the control path
- it makes more sense to relax the barrier in the fast path, at the PMD level.
relaxing the fundamental rte_io_x barriers APIs requires scrutinizations for
each PMDs which use the barriers directly or indirectly.
V2:
- remove virtio_pci_read/write64 APIs definitions, they are not needed and generate compiling errors like " error: unused function 'virtio_pci_write64' [-Werror,-Wunused-function]"
- update the reference link to kernel source code
---
drivers/net/i40e/i40e_rxtx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
index fd1ae80da..8c0f7cc67 100644
--- a/drivers/net/i40e/i40e_rxtx.c
+++ b/drivers/net/i40e/i40e_rxtx.c
@@ -1248,7 +1248,8 @@ i40e_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
(unsigned) txq->port_id, (unsigned) txq->queue_id,
(unsigned) tx_id, (unsigned) nb_tx);
- I40E_PCI_REG_WRITE(txq->qtx_tail, tx_id);
+ rte_cio_wmb();
+ I40E_PCI_REG_WRITE_RELAXED(txq->qtx_tail, tx_id);
txq->tx_tail = tx_id;
return nb_tx;
--
2.17.1
next prev parent reply other threads:[~2020-02-12 6:01 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-22 15:27 [dpdk-dev] [PATCH v1 0/3] relax io barrier for aarch64 and use smp barriers for virtual pci memory Gavin Hu
2019-10-22 15:27 ` [dpdk-dev] [PATCH v1 1/3] eal/arm64: relax the io barrier for aarch64 Gavin Hu
2019-10-22 15:27 ` [dpdk-dev] [PATCH v1 2/3] net/virtio: virtual PCI requires smp barriers Gavin Hu
2019-10-22 15:27 ` [dpdk-dev] [PATCH v1 3/3] crypto/virtio: " Gavin Hu
2019-10-23 8:22 ` [dpdk-dev] [PATCH v1 0/3] relax io barrier for aarch64 and use smp barriers for virtual pci memory Maxime Coquelin
2019-11-07 1:13 ` Gavin Hu (Arm Technology China)
2019-12-20 3:09 ` [dpdk-dev] [PATCH v2 " Gavin Hu
2019-12-20 3:09 ` [dpdk-dev] [PATCH v2 1/3] eal/arm64: relax the io barrier for aarch64 Gavin Hu
2019-12-20 3:33 ` Jerin Jacob
2019-12-20 3:38 ` Jerin Jacob
2019-12-20 4:19 ` Gavin Hu
2019-12-20 4:34 ` Jerin Jacob
2019-12-20 6:32 ` Gavin Hu
2019-12-20 6:55 ` Jerin Jacob
2019-12-23 9:14 ` Gavin Hu
2019-12-23 9:19 ` Jerin Jacob
2019-12-23 10:16 ` Gavin Hu
2020-01-02 9:51 ` Jerin Jacob
2020-01-03 6:30 ` Gavin Hu
2020-01-03 7:34 ` Jerin Jacob
2020-01-03 9:12 ` Gavin Hu
2019-12-20 3:09 ` [dpdk-dev] [PATCH v2 2/3] net/virtio: virtual PCI requires smp barriers Gavin Hu
2019-12-20 8:17 ` Tiwei Bie
2019-12-20 10:19 ` Gavin Hu
2019-12-20 3:09 ` [dpdk-dev] [PATCH v2 3/3] crypto/virtio: " Gavin Hu
2020-02-08 13:48 ` [dpdk-dev] [PATCH v3] net/i40e: relaxed barrier in the tx fastpath Gavin Hu
2020-02-11 2:11 ` Ye Xiaolong
2020-02-12 6:02 ` Gavin Hu
2020-02-15 8:25 ` Jerin Jacob
2020-02-12 5:56 ` Gavin Hu [this message]
2020-02-15 15:16 ` [dpdk-dev] [PATCH v4] " Ye Xiaolong
2020-02-16 9:51 ` Thomas Monjalon
2020-02-16 16:38 ` Ye Xiaolong
2020-02-16 17:36 ` Thomas Monjalon
[not found] <VI1PR08MB5376173EB8A8A58BC93CD2398F150@VI1PR08MB5376.eurprd08.prod.outlook.com>
2020-02-14 8:04 ` Gavin Hu
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