patches for DPDK stable branches
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From: Ye Xiaolong <xiaolong.ye@intel.com>
To: Gavin Hu <gavin.hu@arm.com>
Cc: dev@dpdk.org, nd@arm.com, david.marchand@redhat.com,
	thomas@monjalon.net, jerinj@marvell.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: Re: [dpdk-stable] [PATCH v4] net/i40e: relaxed barrier in the tx fastpath
Date: Sat, 15 Feb 2020 23:16:35 +0800	[thread overview]
Message-ID: <20200215151635.GH16933@intel.com> (raw)
In-Reply-To: <20200212055621.118363-1-gavin.hu@arm.com>

s/relaxed/relax

On 02/12, Gavin Hu wrote:
>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
>

Applied to dpdk-next-net-intel with Jerin's Reviewed-by tag, Thanks.

  reply	other threads:[~2020-02-15 15:18 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1571758074-16445-1-git-send-email-gavin.hu@arm.com>
2020-02-12  5:56 ` Gavin Hu
2020-02-15 15:16   ` Ye Xiaolong [this message]
2020-02-16  9:51     ` Thomas Monjalon
2020-02-16 16:38       ` Ye Xiaolong
2020-02-16 17:36         ` Thomas Monjalon

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