From: Lorenzo Bianconi <lorenzo@kernel.org>
To: Toshiaki Makita <toshiaki.makita1@gmail.com>
Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, davem@davemloft.net,
kuba@kernel.org, ast@kernel.org, daniel@iogearbox.net,
lorenzo.bianconi@redhat.com, brouer@redhat.com, toke@redhat.com
Subject: Re: [PATCH v2 bpf-next] net: veth: alloc skb in bulk for ndo_xdp_xmit
Date: Fri, 29 Jan 2021 22:41:14 +0100 [thread overview]
Message-ID: <20210129214114.GA20729@lore-desk> (raw)
In-Reply-To: <36298336-72f9-75a5-781e-7cb01dac1702@gmail.com>
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> On 2021/01/29 4:41, Lorenzo Bianconi wrote:
> > Split ndo_xdp_xmit and ndo_start_xmit use cases in veth_xdp_rcv routine
> > in order to alloc skbs in bulk for XDP_PASS verdict.
> > Introduce xdp_alloc_skb_bulk utility routine to alloc skb bulk list.
> > The proposed approach has been tested in the following scenario:
> >
> > eth (ixgbe) --> XDP_REDIRECT --> veth0 --> (remote-ns) veth1 --> XDP_PASS
> >
> > XDP_REDIRECT: xdp_redirect_map bpf sample
> > XDP_PASS: xdp_rxq_info bpf sample
> >
> > traffic generator: pkt_gen sending udp traffic on a remote device
> >
> > bpf-next master: ~3.64Mpps
> > bpf-next + skb bulking allocation: ~3.75Mpps
> >
> > Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> > ---
> ...
> > +/* frames array contains VETH_XDP_BATCH at most */
> > +static void veth_xdp_rcv_batch(struct veth_rq *rq, void **frames,
> > + int n_xdpf, struct veth_xdp_tx_bq *bq,
> > + struct veth_stats *stats)
> > +{
> > + void *skbs[VETH_XDP_BATCH];
> > + int i, n_skb = 0;
> > +
> > + for (i = 0; i < n_xdpf; i++) {
> > + struct xdp_frame *frame = frames[i];
> > +
> > + stats->xdp_bytes += frame->len;
> > + frame = veth_xdp_rcv_one(rq, frame, bq, stats);
> > + if (frame)
> > + frames[n_skb++] = frame;
> > + }
>
> Maybe we can move this block to veth_xdp_rcv() and make the logic even more simple?
>
> Something like this:
>
> static int veth_xdp_rcv(struct veth_rq *rq, int budget,
> ...
> if (veth_is_xdp_frame(ptr)) {
> struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
>
> stats->xdp_bytes += frame->len;
> frame = veth_xdp_rcv_one(rq, frame, bq, stats);
> if (frame) {
> xdpf[n_xdpf++] = frame;
> if (n_xdpf == VETH_XDP_BATCH) {
> veth_xdp_rcv_batch(rq, xdpf, n_xdpf, bq,
> stats);
> n_xdpf = 0;
> }
> }
>
> Then we can fully make use of skb bulk allocation as xdpf[] does not include
> frames which may be XDP_TX'ed or XDP_REDIRECT'ed.
>
> WDYT?
I gues the code is more readable, I will fix in v3. Thanks.
Regards,
Lorenzo
>
> Toshiaki Makita
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prev parent reply other threads:[~2021-01-29 21:42 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <415937741661ac331be09c0e59b4ff1eacfee782.1611861943.git.lorenzo@kernel.org>
[not found] ` <20210129170216.6a879619@carbon>
2021-01-29 19:17 ` [PATCH v2 bpf-next] net: veth: alloc skb in bulk for ndo_xdp_xmit Jesper Dangaard Brouer
2021-01-29 21:46 ` Lorenzo Bianconi
2021-01-29 21:49 ` Lorenzo Bianconi
2021-02-01 10:06 ` Jesper Dangaard Brouer
[not found] ` <36298336-72f9-75a5-781e-7cb01dac1702@gmail.com>
2021-01-29 21:41 ` Lorenzo Bianconi [this message]
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