On 11/01/2014 07:00 PM, David Miller wrote:

From: Denis Kirjanov <redacted>
Date: Sat, 1 Nov 2014 21:49:27 +0400

quoted

David, you need a feedback from other guys to apply this patch, right?

Alexei wanted some output before/after the patch.
Michael Ellerman wanted the explanation what a BPF_ANC | SKF_AD_PKTTYPE means.

The BPF_ANC | SKF_AD_PKTTYPE case means that this is an ancillary
operation aka BPF extension which loads the value of skb->pkt_type
into the accumulator.

A similar transformation, that is, from BPF into eBPF insns can be
found in convert_bpf_extensions() in the SKF_AD_PKTTYPE case, or
commit 709f6c58d4dc ("sparc: bpf_jit: add SKF_AD_PKTTYPE support
to JIT") that recently enabled the same in sparc.

quoted

So I'm waiting  the ack/nack from them...

I don't really think performance metrics are necessary just for adding
SKF_AD_PKTTYPE support, that's sort of an over the top requirement
if you ask me.

Right, lib/test_bpf.c actually brings the quoted output w/ numbers
for free. I think the important point was that the 'After:' case
with ``echo 1 > /proc/sys/net/core/bpf_jit_enable'' runs through for
that test case, which has been shown here.

It's pretty obvious that we should support as many operations as
possible to each JIT, because all of program has to do is use that
unsupported opcode and then we have none of that program being JIT'd.