From: Lorenzo Bianconi <lorenzo@kernel.org>
To: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: davem@davemloft.net, netdev@vger.kernel.org, lorenzo.bianconi@redhat.com
Subject: Re: [PATCH net] net: socionext: netsec: fix xdp stats accounting
Date: Fri, 11 Oct 2019 17:58:47 +0200 [thread overview]
Message-ID: <20191011155847.GA4220@localhost.localdomain> (raw)
In-Reply-To: <20191011151628.GA12122@apalos.home>
[-- Attachment #1: Type: text/plain, Size: 3067 bytes --]
> On Fri, Oct 11, 2019 at 05:15:03PM +0300, Ilias Apalodimas wrote:
> > Hi Lorenzo,
> >
> > On Fri, Oct 11, 2019 at 03:45:38PM +0200, Lorenzo Bianconi wrote:
> > > Increment netdev rx counters even for XDP_DROP verdict. Moreover report
> > > even tx bytes for xdp buffers (TYPE_NETSEC_XDP_TX or
> > > TYPE_NETSEC_XDP_NDO)
> >
> > The RX counters work fine. The TX change is causing a panic though and i am
> > looking into it since your patch seems harmless. In any case please don't merge
> > this yet
> >
>
> Ok i think i know what's going on.
> Our clean TX routine has a netdev_completed_queue(). This is properly accounted
> for on netsec_netdev_start_xmit() which calls netdev_sent_queue().
>
> Since the XDP never had support for that you need to account for the extra bytes
> in netsec_xdp_queue_one(). That's what triggering the BUG_ON
> (lib/dynamic_queue_limits.c line 27)
Hi Ilias,
yes, right. We need to account pending xdp buffer len on tx side.
>
> Since netdev_completed_queue() enforces barrier() and in some cases smp_mb() i
> think i'd prefer it per function, although it looks uglier.
> Can you send a patch with this call in netsec_xdp_queue_one()? If we cant
> measure any performance difference i am fine with adding it in that only.
If this introduce a performance penalty we can just account netdev tx_bytes
directly (maybe it is ugly)
Regards,
Lorenzo
>
> Thanks
> /Ilias
>
> > Thanks
> > /Ilias
> >
> > > Fixes: ba2b232108d3 ("net: netsec: add XDP support")
> > > Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> > > ---
> > > just compiled not tested on a real device
> > > ---
> > > drivers/net/ethernet/socionext/netsec.c | 4 ++--
> > > 1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/net/ethernet/socionext/netsec.c b/drivers/net/ethernet/socionext/netsec.c
> > > index f9e6744d8fd6..b1c2a79899b3 100644
> > > --- a/drivers/net/ethernet/socionext/netsec.c
> > > +++ b/drivers/net/ethernet/socionext/netsec.c
> > > @@ -252,7 +252,6 @@
> > > #define NETSEC_XDP_CONSUMED BIT(0)
> > > #define NETSEC_XDP_TX BIT(1)
> > > #define NETSEC_XDP_REDIR BIT(2)
> > > -#define NETSEC_XDP_RX_OK (NETSEC_XDP_PASS | NETSEC_XDP_TX | NETSEC_XDP_REDIR)
> > >
> > > enum ring_id {
> > > NETSEC_RING_TX = 0,
> > > @@ -661,6 +660,7 @@ static bool netsec_clean_tx_dring(struct netsec_priv *priv)
> > > bytes += desc->skb->len;
> > > dev_kfree_skb(desc->skb);
> > > } else {
> > > + bytes += desc->xdpf->len;
> > > xdp_return_frame(desc->xdpf);
> > > }
> > > next:
> > > @@ -1030,7 +1030,7 @@ static int netsec_process_rx(struct netsec_priv *priv, int budget)
> > >
> > > next:
> > > if ((skb && napi_gro_receive(&priv->napi, skb) != GRO_DROP) ||
> > > - xdp_result & NETSEC_XDP_RX_OK) {
> > > + xdp_result) {
> > > ndev->stats.rx_packets++;
> > > ndev->stats.rx_bytes += xdp.data_end - xdp.data;
> > > }
> > > --
> > > 2.21.0
> > >
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]
prev parent reply other threads:[~2019-10-11 15:58 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-11 13:45 [PATCH net] net: socionext: netsec: fix xdp stats accounting Lorenzo Bianconi
2019-10-11 14:15 ` Ilias Apalodimas
2019-10-11 15:16 ` Ilias Apalodimas
2019-10-11 15:58 ` Lorenzo Bianconi [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191011155847.GA4220@localhost.localdomain \
--to=lorenzo@kernel.org \
--cc=davem@davemloft.net \
--cc=ilias.apalodimas@linaro.org \
--cc=lorenzo.bianconi@redhat.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).