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.
