From: Jakub Kicinski <jakub.kicinski@netronome.com>
To: Jose Abreu <Jose.Abreu@synopsys.com>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
Joao Pinto <Joao.Pinto@synopsys.com>,
Giuseppe Cavallaro <peppe.cavallaro@st.com>,
Alexandre Torgue <alexandre.torgue@st.com>,
"David S. Miller" <davem@davemloft.net>,
Maxime Coquelin <mcoquelin.stm32@gmail.com>,
"linux-stm32@st-md-mailman.stormreply.com"
<linux-stm32@st-md-mailman.stormreply.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH net-next 4/4] net: stmmac: Always use TX coalesce timer value when rescheduling
Date: Mon, 16 Dec 2019 12:16:05 -0800 [thread overview]
Message-ID: <20191216121605.4780302d@cakuba.netronome.com> (raw)
In-Reply-To: <BN8PR12MB3266BDA48CE9F65D564B0918D3510@BN8PR12MB3266.namprd12.prod.outlook.com>
On Mon, 16 Dec 2019 09:20:53 +0000, Jose Abreu wrote:
> > > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > > index f61780ae30ac..726a17d9cc35 100644
> > > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > > @@ -1975,7 +1975,7 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue)
> > >
> > > /* We still have pending packets, let's call for a new scheduling */
> > > if (tx_q->dirty_tx != tx_q->cur_tx)
> > > - mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(10));
> > > + mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(priv->tx_coal_timer));
> >
> > I think intent of this code is to re-check the ring soon. The same
> > value of 10 is used in stmmac_tx_timer() for quick re-check.
> >
> > tx_coal_timer defaults to 1000, so it's quite a jump from 10 to 1000.
> >
> > I think the commit message leaves too much unsaid.
> >
> > Also if you want to change to the ethtool timeout value, could you move
> > stmmac_tx_timer_arm() and reuse that helper?
>
> Yeah, it's a quick re-check but 10us can be too low on some speeds and
> leads to CPU useless-looping. The intent is to let this always be
> configurable by user.
Okay, please do mention the bump from 10us to the default of 1ms in the
commit message, though.
prev parent reply other threads:[~2019-12-16 20:16 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-10 19:54 [PATCH net-next 0/4] net: stmmac: Improvements for -next Jose Abreu
2019-12-10 19:54 ` [PATCH net-next 1/4] net: stmmac: Print more information in DebugFS DMA Capabilities file Jose Abreu
2019-12-10 19:54 ` [PATCH net-next 2/4] net: stmmac: Always arm TX Timer at end of transmission start Jose Abreu
2019-12-10 19:54 ` [PATCH net-next 3/4] net: stmmac: Let TX and RX interrupts be independently enabled/disabled Jose Abreu
2019-12-14 20:36 ` Jakub Kicinski
2019-12-16 9:18 ` Jose Abreu
2019-12-16 20:14 ` Jakub Kicinski
2019-12-10 19:54 ` [PATCH net-next 4/4] net: stmmac: Always use TX coalesce timer value when rescheduling Jose Abreu
2019-12-14 20:28 ` Jakub Kicinski
2019-12-16 9:20 ` Jose Abreu
2019-12-16 20:16 ` Jakub Kicinski [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=20191216121605.4780302d@cakuba.netronome.com \
--to=jakub.kicinski@netronome.com \
--cc=Joao.Pinto@synopsys.com \
--cc=Jose.Abreu@synopsys.com \
--cc=alexandre.torgue@st.com \
--cc=davem@davemloft.net \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-stm32@st-md-mailman.stormreply.com \
--cc=mcoquelin.stm32@gmail.com \
--cc=netdev@vger.kernel.org \
--cc=peppe.cavallaro@st.com \
/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).