From: Lorenzo Bianconi <lorenzo@kernel.org>
To: Shay Agroskin <shayagr@amazon.com>
Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, davem@davemloft.net,
lorenzo.bianconi@redhat.com, brouer@redhat.com,
echaudro@redhat.com, sameehj@amazon.com, kuba@kernel.org,
john.fastabend@gmail.com, daniel@iogearbox.net, ast@kernel.org
Subject: Re: [PATCH v2 net-next 3/9] net: mvneta: update mb bit before passing the xdp buffer to eBPF layer
Date: Sun, 6 Sep 2020 11:05:57 +0200 [thread overview]
Message-ID: <20200906090557.GB2785@lore-desk> (raw)
In-Reply-To: <pj41zly2lnpdfn.fsf@u68c7b5b1d2d758.ant.amazon.com>
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[...]
> > rx_desc->buf_phys_addr,
> > len, dma_dir);
> > - if (data_len > 0 && sinfo->nr_frags < MAX_SKB_FRAGS) {
> > - skb_frag_t *frag = &sinfo->frags[sinfo->nr_frags];
> > + if (data_len > 0 && *nfrags < MAX_SKB_FRAGS) {
> > + skb_frag_t *frag = &sinfo->frags[*nfrags];
> > skb_frag_off_set(frag, pp->rx_offset_correction);
> > skb_frag_size_set(frag, data_len);
> > __skb_frag_set_page(frag, page);
> > - sinfo->nr_frags++;
> > + *nfrags = *nfrags + 1;
>
> nit, why do you use nfrags variable instead of sinfo->nr_frags (as it was
> before this patch) ?
> You doesn't seem to use the nfrags variable in the
> caller function and you update nr_frags as well.
> If it's used in a different patch (haven't
> reviewed it all yet), maybe move it to that patch ? (sorry in
> advance if I missed the logic here)
nfrags pointer is used to avoid the sinfo->nr_frags initialization in
mvneta_swbm_rx_frame() since skb_shared_info is not in the cache usually.
AFAIK the hw does not provide the info "this is the second descriptor" but
just "this the frist/last descriptor".
Regards,
Lorenzo
>
> > +
> > + if (rx_desc->status & MVNETA_RXD_LAST_DESC) {
> > + sinfo->nr_frags = *nfrags;
> > + xdp->mb = true;
> > + }
> > rx_desc->buf_phys_addr = 0;
> > ...
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next prev parent reply other threads:[~2020-09-06 9:06 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-03 20:58 [PATCH v2 net-next 0/9] mvneta: introduce XDP multi-buffer support Lorenzo Bianconi
2020-09-03 20:58 ` [PATCH v2 net-next 1/9] xdp: introduce mb in xdp_buff/xdp_frame Lorenzo Bianconi
2020-09-04 1:07 ` Alexei Starovoitov
2020-09-04 7:19 ` Jesper Dangaard Brouer
2020-09-04 15:15 ` David Ahern
2020-09-04 15:59 ` Jesper Dangaard Brouer
2020-09-04 16:30 ` David Ahern
2020-09-07 18:02 ` Jesper Dangaard Brouer
2020-09-08 1:22 ` David Ahern
2020-09-03 20:58 ` [PATCH v2 net-next 2/9] xdp: initialize xdp_buff mb bit to 0 in all XDP drivers Lorenzo Bianconi
2020-09-04 7:35 ` Jesper Dangaard Brouer
2020-09-04 7:54 ` Lorenzo Bianconi
2020-09-03 20:58 ` [PATCH v2 net-next 3/9] net: mvneta: update mb bit before passing the xdp buffer to eBPF layer Lorenzo Bianconi
2020-09-06 7:33 ` Shay Agroskin
2020-09-06 9:05 ` Lorenzo Bianconi [this message]
2020-09-03 20:58 ` [PATCH v2 net-next 4/9] xdp: add multi-buff support to xdp_return_{buff/frame} Lorenzo Bianconi
2020-09-03 20:58 ` [PATCH v2 net-next 5/9] net: mvneta: add multi buffer support to XDP_TX Lorenzo Bianconi
2020-09-06 7:20 ` Shay Agroskin
2020-09-06 8:43 ` Lorenzo Bianconi
2020-09-03 20:58 ` [PATCH v2 net-next 6/9] bpf: helpers: add bpf_xdp_adjust_mb_header helper Lorenzo Bianconi
2020-09-04 1:09 ` Alexei Starovoitov
2020-09-04 8:07 ` Lorenzo Bianconi
2020-09-04 1:13 ` Alexei Starovoitov
2020-09-04 7:50 ` Lorenzo Bianconi
2020-09-04 13:52 ` Jesper Dangaard Brouer
2020-09-04 14:27 ` Lorenzo Bianconi
2020-09-04 6:47 ` John Fastabend
2020-09-04 9:45 ` Lorenzo Bianconi
2020-09-04 15:23 ` John Fastabend
2020-09-06 13:36 ` Lorenzo Bianconi
2020-09-08 19:57 ` John Fastabend
2020-09-08 21:31 ` Lorenzo Bianconi
2020-09-09 20:51 ` Lorenzo Bianconi
2020-09-03 20:58 ` [PATCH v2 net-next 7/9] bpf: helpers: add multibuffer support Lorenzo Bianconi
2020-09-03 21:24 ` Maciej Fijalkowski
2020-09-04 9:47 ` Lorenzo Bianconi
2020-09-03 20:58 ` [PATCH v2 net-next 8/9] samples/bpf: add bpf program that uses xdp mb helpers Lorenzo Bianconi
2020-09-03 20:58 ` [PATCH v2 net-next 9/9] net: mvneta: enable jumbo frames for XDP Lorenzo Bianconi
2020-09-04 1:08 ` [PATCH v2 net-next 0/9] mvneta: introduce XDP multi-buffer support Alexei Starovoitov
2020-09-04 7:40 ` Lorenzo Bianconi
2020-09-04 5:41 ` John Fastabend
2020-09-04 7:39 ` Lorenzo Bianconi
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