On Mon, 25 Nov 2019 at 12:18, Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote: > > Björn Töpel <bjorn.topel@xxxxxxxxx> writes: > > > From: Björn Töpel <bjorn.topel@xxxxxxxxx> > > > > The xdp_call.h header wraps a more user-friendly API around the BPF > > dispatcher. A user adds a trampoline/XDP caller using the > > DEFINE_XDP_CALL macro, and updates the BPF dispatcher via > > xdp_call_update(). The actual dispatch is done via xdp_call(). > > > > Note that xdp_call() is only supported for builtin drivers. Module > > builds will fallback to bpf_prog_run_xdp(). > > I don't like this restriction. Distro kernels are not likely to start > shipping all the network drivers builtin, so they won't benefit from the > performance benefits from this dispatcher. > > What is the reason these dispatcher blocks have to reside in the driver? > Couldn't we just allocate one system-wide, and then simply change > bpf_prog_run_xdp() to make use of it transparently (from the driver > PoV)? That would also remove the need to modify every driver... > Good idea! I'll try that out. Thanks for the suggestion! Björn > -Toke >
