> -----Original Message----- > From: Stephen Hemminger [mailto:step...@networkplumber.org] > Sent: Friday, September 27, 2019 01:15 > To: Wang, Haiyue <haiyue.w...@intel.com> > Cc: dev@dpdk.org; Yigit, Ferruh <ferruh.yi...@intel.com>; Ye, Xiaolong > <xiaolong...@intel.com>; > Kinsella, Ray <ray.kinse...@intel.com>; Iremonger, Bernard > <bernard.iremon...@intel.com>; Sun, Chenmin > <chenmin....@intel.com> > Subject: Re: [dpdk-dev] [PATCH v1 0/4] get Rx/Tx packet burst mode information > > On Thu, 26 Sep 2019 16:36:09 +0000 > "Wang, Haiyue" <haiyue.w...@intel.com> wrote: > > > Hi Stephen, > > > > > -----Original Message----- > > > From: Stephen Hemminger [mailto:step...@networkplumber.org] > > > Sent: Thursday, September 26, 2019 23:57 > > > To: Wang, Haiyue <haiyue.w...@intel.com> > > > Cc: dev@dpdk.org; Yigit, Ferruh <ferruh.yi...@intel.com>; Ye, Xiaolong > > > <xiaolong...@intel.com>; > > > Kinsella, Ray <ray.kinse...@intel.com>; Iremonger, Bernard > > > <bernard.iremon...@intel.com>; Sun, > Chenmin > > > <chenmin....@intel.com> > > > Subject: Re: [dpdk-dev] [PATCH v1 0/4] get Rx/Tx packet burst mode > > > information > > > > > > On Thu, 26 Sep 2019 19:48:14 +0800 > > > Haiyue Wang <haiyue.w...@intel.com> wrote: > > > > > > > RFCv3 -> v1: > > > > https://patchwork.dpdk.org/patch/59103/ > > > > https://patchwork.dpdk.org/patch/59104/ > > > > https://patchwork.dpdk.org/patch/59105/ > > > > https://patchwork.dpdk.org/patch/59106/ > > > > 1). Use the function 'rte_bsf64' to iterate the options for > > > > getting the name. > > > > > > > > Haiyue Wang (4): > > > > ethdev: add the API for getting burst mode information > > > > net/i40e: support to get the Rx/Tx burst mode > > > > net/ice: support to get the Rx/Tx burst mode > > > > app/testpmd: show the Rx/Tx burst mode description > > > > > > > > app/test-pmd/config.c | 29 +++++++++ > > > > doc/guides/rel_notes/release_19_11.rst | 9 +++ > > > > drivers/net/i40e/i40e_ethdev.c | 2 + > > > > drivers/net/i40e/i40e_ethdev.h | 4 ++ > > > > drivers/net/i40e/i40e_rxtx.c | 72 +++++++++++++++++++++ > > > > drivers/net/ice/ice_ethdev.c | 2 + > > > > drivers/net/ice/ice_rxtx.c | 54 ++++++++++++++++ > > > > drivers/net/ice/ice_rxtx.h | 4 ++ > > > > lib/librte_ethdev/rte_ethdev.c | 75 ++++++++++++++++++++++ > > > > lib/librte_ethdev/rte_ethdev.h | 82 ++++++++++++++++++++++++ > > > > lib/librte_ethdev/rte_ethdev_core.h | 5 ++ > > > > lib/librte_ethdev/rte_ethdev_version.map | 5 ++ > > > > 12 files changed, 343 insertions(+) > > > > > > > > > > A couple of meta comments: > > > 1) Could this be part of dev_info_get somehow? > > > > > > > https://patchwork.dpdk.org/patch/57624/ > > 'Think of a better way that doesn't break ABI.' ;-) > > That comment was made relative to 19.08, but 19.11 is the time where > API/ABI breakage is allowed. >
Since 'rte_eth_dev_info_get(uint16_t port_id, struct rte_eth_dev_info *dev_info)' focuses on 'port' level, the new rx/tx_burst_mode API can support 'queue' level: 'rte_eth_tx_burst_mode_get(uint16_t port_id, uint16_t queue_id ...', in other words, PMD can optimize their queues in Vector/Scalar/... modes for each queue, not have to just one mode for all queues at the same time, this API can return "Per Queue" information. > > > 2) Why should application care? Is this just a test hook? > > > > https://patches.dpdk.org/cover/57623/ > > This is from FD.io VPP's bug, and finally, we come out > > this API for application accessing the burst mode information. > > It can be used as a simple trace or something like performance > > analysis like why slow ? Not in vector, anyway, application can > > get this burst mode information now, not just open PMD debug log > > level. > > From an architecture perspective, diagnostics are good but VPP is probably > taking that too far. It is possible to expose local symbols if they > want to keep using dlsym() by adjusting linker flags. It is more that VPP > is stripping everything. Since VPP has chosen to go their own > way is fixable inside VPP without changing DPDK. Also, long term VPP is > going away from using DPDK drivers. Probably soon they will have their > own drivers for i40e and ice anyway. > > > The basis of my concern is that this is one of those kind of API's > that creates long term technical debt around supporting it as other > things change. At first, we use 'string format' to make VPP happy, now, we use bit-fields for general use. People come, people go, even VPP left DPDK, now, testpmd is the first user, and I think it is good for 'test' the PMD with friendly information: testpmd> show rxq info 0 0 ********************* Infos for port 0 , RX queue 0 ********************* Mempool: mbuf_pool_socket_0 RX prefetch threshold: 0 RX host threshold: 0 RX writeback threshold: 0 RX free threshold: 32 RX drop packets: off RX deferred start: off RX scattered packets: off Number of RXDs: 1024 Burst mode: Vector AVX2 =============> direct information, not have to check the code and open debug to make sure every setting is right. testpmd> show txq info 0 0 ********************* Infos for port 0 , TX queue 0 ********************* TX prefetch threshold: 32 TX host threshold: 0 TX writeback threshold: 0 TX RS threshold: 32 TX free threshold: 32 TX deferred start: off Number of TXDs: 1024 Burst mode: Vector AVX2 =============>
