> On Jul 22, 2019, at 9:45 AM, Ferruh Yigit <ferruh.yi...@intel.com> wrote: > > On 7/22/2019 2:07 PM, Slava Ovsiienko wrote: >>> -----Original Message----- >>> From: Ferruh Yigit <ferruh.yi...@intel.com> >>> Sent: Monday, July 22, 2019 14:53 >>> To: Slava Ovsiienko <viachesl...@mellanox.com>; dev@dpdk.org >>> Cc: Yongseok Koh <ys...@mellanox.com> >>> Subject: Re: [dpdk-dev] [PATCH v4 6/8] net/mlx5: introduce Tx burst routine >>> template >>> >>> On 7/21/2019 3:24 PM, Viacheslav Ovsiienko wrote: >>>> Mellanox NICs support the wide set of Tx offloads. The supported >>>> offloads are reported by the mlx5 PMD in rte_eth_dev_info >>>> tx_offload_capa field. An application may choose any combination of >>>> supported offloads and configure the device appropriately. Some of Tx >>>> offloads may be not requested by application, or ever all of them may be >>> omitted. >>>> Most of the Tx offloads require some code branches in tx_burst routine >>>> to support ones. If Tx offload is not requested the tx_burst routine >>>> code may be significantly simplified and consume less CPU cycles. >>>> >>>> For example, if application does not engage TSO offload this code can >>>> be omitted, if multi-segment packet is not supposed the tx_burst may >>>> assume single mbuf packets only, etc. >>>> >>>> Currently, the mlx5 PMD implements multiple tx_burst subroutines for >>>> most common combinations of requested Tx offloads, each branch has its >>>> own dedicated implementation. It is not very easy to update, support >>>> and develop such kind of code - multiple branches impose the multiple >>>> points to process. Also many of frequently requested offload >>>> combinations are not supported yet. That leads to selecting of not >>>> completely matching tx_burst routine and harms the performance. >>>> >>>> This patch introduces the new approach for tx_burst code. It is >>>> proposed to develop the unified template for tx_burst routine, which >>>> supports all the Tx offloads and takes the compile time defined >>>> parameter describing the supposed set of supported offloads. On the >>>> base of this template, the compiler is able to generate multiple >>>> tx_burst routines highly optimized for the statically specified set of Tx >>> offloads. >>>> Next, in runtime, at Tx queue configuration the best matching >>>> optimized implementation of tx_burst is chosen. >>>> >>>> This patch intentionally omits the template internal implementation, >>>> but just introduces the template itself to emboss the approach of the >>>> multiple specially tuned tx_burst routines. >>>> >>>> Signed-off-by: Viacheslav Ovsiienko <viachesl...@mellanox.com> >>> >>> Getting following build error with icc, can you please check? >>> >>> >>> .../dpdk/drivers/net/mlx5/mlx5_rxtx.c(4649): error #191: type qualifier is >>> meaningless on cast type >>> >>> >>> MLX5_TXOFF_DECL(full_empw, >>> >> Sorry, I have no icc at my disposal now. What I can say (sorry again, it is >> obvious) >> - It definitely does not like the MLX5_TXOFF_DECL macro. Most likely - >> "restrict" qualifier, I think. >> >> With best regards, Slava >> > > Hi Slava, > > I was hoping error log can give enough hint, but I tested by removing the > 'restrict' keyword and it fixed the icc warning. > > Can you please check if the 'icc' is right and 'restrict' is meaningless, if > so > can you please send a patch to remove it? > else please let me know and I can make a patch to disable the specific icc > warning.
Yes, it looks quite obvious from the error message. mlx5_tx_burst_tmpl() has the qualifier, so compiler thinks it isn't necessary. Slava is testing it with gcc/clang. He will get back to you soon. Thanks, Yongseok
