> -----Original Message----- > From: Stephen Hemminger [mailto:step...@networkplumber.org] > Sent: Tuesday, August 13, 2019 01:29 > To: Wang, Haiyue <haiyue.w...@intel.com> > Cc: David Marchand <david.march...@redhat.com>; dev <dev@dpdk.org> > Subject: Re: [dpdk-dev] [RFC v1 0/3] show the Rx/Tx burst description field > > On Mon, 12 Aug 2019 16:00:27 +0000 > "Wang, Haiyue" <haiyue.w...@intel.com> wrote: > > > > -----Original Message----- > > > From: Stephen Hemminger [mailto:step...@networkplumber.org] > > > Sent: Monday, August 12, 2019 23:54 > > > To: Wang, Haiyue <haiyue.w...@intel.com> > > > Cc: David Marchand <david.march...@redhat.com>; dev <dev@dpdk.org> > > > Subject: Re: [dpdk-dev] [RFC v1 0/3] show the Rx/Tx burst description > > > field > > > > > > On Mon, 12 Aug 2019 15:42:45 +0000 > > > "Wang, Haiyue" <haiyue.w...@intel.com> wrote: > > > > > > > > -----Original Message----- > > > > > From: Stephen Hemminger [mailto:step...@networkplumber.org] > > > > > Sent: Monday, August 12, 2019 23:38 > > > > > To: David Marchand <david.march...@redhat.com> > > > > > Cc: Wang, Haiyue <haiyue.w...@intel.com>; dev <dev@dpdk.org> > > > > > Subject: Re: [dpdk-dev] [RFC v1 0/3] show the Rx/Tx burst description > > > > > field > > > > > > > > > > On Mon, 12 Aug 2019 16:27:11 +0200 > > > > > David Marchand <david.march...@redhat.com> wrote: > > > > > > > > > > > On Mon, Aug 12, 2019 at 4:20 PM Haiyue Wang <haiyue.w...@intel.com> > > > > > > wrote: > > > > > > > > > > > > > > Since some PMDs have multi-path for Rx/Tx, FD.io VPP will tell > > > > > > > you in > > > > > > > the Debug CLI what rx/tx function is being used: > > > > > > > #show hardware-interface > > > > > > > > > > > > > > tx burst function: ice_xmit_pkts > > > > > > > rx burst function: ice_recv_scattered_pkts > > > > > > > > > > > > > > But if the tx/rx is static, then 'dladdr' will return nil: > > > > > > > > > > > > > > tx burst function: (nil) │······················ > > > > > > > rx burst function: (nil) │······················ > > > > > > > > > > > > > > For making things consistent and gracefull, we introduce an new > > > > > > > string > > > > > > > field to describe the Rx/Tx burst information. This is > > > > > > > vendor-neutral, > > > > > > > it is used to identify the Rx/Tx burst selection if the PMD has > > > > > > > more > > > > > > > than one. > > > > > > > > > > > > > > If a PMD supports this, then rxqinfo/txqinfo->burst_info[0] != > > > > > > > '\0'. > > > > > > > > > > > > The rx/tx handlers are the same for all queues of a ethdev port. > > > > > > What is the added value to put this in a per queue api ? > > > > > > > > > > With some symbol table lookup tools it is possible to do introspection > > > > > to find the symbol from the function pointer. Without breaking > > > > > API/ABI. > > > > > > > > Sounds cool, any link can be reached ? > > > > > > > > VPP uses as below, but will fail for static function. > > > > > > > > static const char * > > > > ptr2sname (void *p) > > > > { > > > > Dl_info info = { 0 }; > > > > > > > > if (dladdr (p, &info) == 0) > > > > return 0; > > > > > > > > return info.dli_sname; > > > > } > > > > > > You need to link with -g and not strip the binary. > > > > You mean gdb debug mode, I guess they will not accept this also. ;-) > > There other ways to mark symbol as non-debug but -g is easiest. > One way is to not mark the function as static. > Other ways are to achieve the same think like __attribute((visibility()) > and linker scripts etc. > > Remember this is VPP you are talking about and it doesn't use standard > DPDK make and flags. >
Yes, this calling is a little geek style, so we are trying to scratch some code to make thing graceful, at least, this makes sense if multiple rx /tx paths are provided. Thanks for your quick feedback, we will try to find other possible design.
