Re: [Bloat] high speed packet and protocol processing in userspace?

[Jesper Dangaard Brouer <brouer@redhat.com>]

On Fri, 17 Mar 2017 13:10:32 +0100
Daniel Borkmann <daniel@iogearbox.net> wrote:

> On 03/17/2017 10:02 AM, Jesper Dangaard Brouer wrote:
> > On Thu, 16 Mar 2017 09:27:44 -0700 Eric Dumazet <eric.dumazet@gmail.com> wrote:  
> >> On Thu, 2017-03-16 at 11:52 -0400, Michael Richardson wrote:  
> >>> Dave Taht <dave.taht@gmail.com> wrote:  
> >>>      > Is it faster to execute 17 bpf vm instructions on (nearly) every
> >>>      > packet, or to use all that old stuff?  
> >>>
> >>> My understanding is that there is a JIT for ebpf.  
> >>
> >> ebpf is pretty fast.  
> >
> > To Dave what kind of arch are you running on?
> > AFAIK you were running on MIPS right?
> > Just checked the kernel tree and I was surprised to see a bpf JIT for mips:
> >
> > $ ls -1 arch/mips/net/bpf_jit*
> > arch/mips/net/bpf_jit_asm.S
> > arch/mips/net/bpf_jit.c
> > arch/mips/net/bpf_jit.h
> >
> > But I don't know what state it is in (Markos?)  
> 
> The JIT is for cBPF right now, but Cavium guys mentioned on netdev
> recently that they're going to implement an eBPF JIT for mips 64.
> 
> You can see current cBPF and eBPF JITs that are supported by the
> kernel via:
> 
> $ git grep BPF_JIT | grep select
> arch/arm/Kconfig:	select HAVE_CBPF_JIT
> arch/arm64/Kconfig:	select HAVE_EBPF_JIT
> arch/mips/Kconfig:	select HAVE_CBPF_JIT if !CPU_MICROMIPS
> arch/powerpc/Kconfig:	select HAVE_CBPF_JIT if !PPC64
> arch/powerpc/Kconfig:	select HAVE_EBPF_JIT if PPC64
> arch/s390/Kconfig:	select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
> arch/sparc/Kconfig:	select HAVE_CBPF_JIT
> arch/x86/Kconfig:	select HAVE_EBPF_JIT			if X86_64

Thanks Daniel, this is very useful information. Doc this:
 https://github.com/netoptimizer/prototype-kernel/commit/ff51c31123de1220

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer