patches for DPDK stable branches
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From: "Gavin Hu (Arm Technology China)" <Gavin.Hu@arm.com>
To: Xiaoyun Li <xiaoyun.li@intel.com>,
	"jingjing.wu@intel.com" <jingjing.wu@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
	"omkar.maslekar@intel.com" <omkar.maslekar@intel.com>,
	"stable@dpdk.org" <stable@dpdk.org>, nd <nd@arm.com>
Subject: Re: [dpdk-stable] [dpdk-dev] [PATCH v2] raw/ntb: fix write memory barrier issue
Date: Mon, 16 Dec 2019 10:49:31 +0000
Message-ID: <VI1PR08MB5376ECC87D2E0907DCFBE47F8F510@VI1PR08MB5376.eurprd08.prod.outlook.com> (raw)
In-Reply-To: <20191216015854.28725-1-xiaoyun.li@intel.com>



> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Xiaoyun Li
> Sent: Monday, December 16, 2019 9:59 AM
> To: jingjing.wu@intel.com
> Cc: dev@dpdk.org; omkar.maslekar@intel.com; Xiaoyun Li
> <xiaoyun.li@intel.com>; stable@dpdk.org
> Subject: [dpdk-dev] [PATCH v2] raw/ntb: fix write memory barrier issue
> 
> All buffers and ring info should be written before tail register update.
> This patch relocates the write memory barrier before updating tail register
> to avoid potential issues.
> 
> Fixes: 11b5c7daf019 ("raw/ntb: add enqueue and dequeue functions")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Xiaoyun Li <xiaoyun.li@intel.com>
> ---
> v2:
>  * Replaced rte_wmb with rte_io_wmb since rte_io_wmb is enough.
> ---
>  drivers/raw/ntb/ntb.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/raw/ntb/ntb.c b/drivers/raw/ntb/ntb.c
> index ad7f6abfd..c7de86f36 100644
> --- a/drivers/raw/ntb/ntb.c
> +++ b/drivers/raw/ntb/ntb.c
> @@ -683,8 +683,8 @@ ntb_enqueue_bufs(struct rte_rawdev *dev,
>  			   sizeof(struct ntb_used) * nb1);
>  		rte_memcpy(txq->tx_used_ring, tx_used + nb1,
>  			   sizeof(struct ntb_used) * nb2);
> +		rte_io_wmb();
As both txq->tx_used_ring and *txq->used_cnt are physically reside in the PCI device side, rte_io_wmb is correct to ensure the ordering.

>  		*txq->used_cnt = txq->last_used;
> -		rte_wmb();
> 
>  		/* update queue stats */
>  		hw->ntb_xstats[NTB_TX_BYTES_ID + off] += bytes;
> @@ -789,8 +789,8 @@ ntb_dequeue_bufs(struct rte_rawdev *dev,
>  			   sizeof(struct ntb_desc) * nb1);
>  		rte_memcpy(rxq->rx_desc_ring, rx_desc + nb1,
>  			   sizeof(struct ntb_desc) * nb2);
> +		rte_io_wmb();
>  		*rxq->avail_cnt = rxq->last_avail;
> -		rte_wmb();
> 
>  		/* update queue stats */
>  		off = NTB_XSTATS_NUM * ((size_t)context + 1);
> --
> 2.17.1

Reviewed-by: Gavin Hu <gavin.hu@arm.com>


  reply	other threads:[~2019-12-16 10:49 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-04 15:19 [dpdk-stable] [PATCH] " Xiaoyun Li
2019-12-14 15:29 ` [dpdk-stable] [dpdk-dev] " Gavin Hu (Arm Technology China)
2019-12-16  1:57   ` Li, Xiaoyun
2019-12-25  3:52     ` Gavin Hu
2019-12-16  1:58 ` [dpdk-stable] [PATCH v2] " Xiaoyun Li
2019-12-16 10:49   ` Gavin Hu (Arm Technology China) [this message]
2019-12-23  7:52     ` [dpdk-stable] [dpdk-dev] " Li, Xiaoyun
2019-12-23  8:38       ` Gavin Hu
2019-12-23  9:35         ` Li, Xiaoyun
2019-12-24 15:46           ` Gavin Hu
2019-12-23  2:38   ` [dpdk-stable] " Wu, Jingjing
2019-12-26  1:46 ` [dpdk-stable] [PATCH] " Wu, Jingjing
2020-01-20  9:04   ` [dpdk-stable] [dpdk-dev] " Thomas Monjalon

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