From: David Miller <davem@davemloft.net>
To: mw@semihalf.com
Cc: gregory.clement@free-electrons.com, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org, thomas.petazzoni@free-electrons.com,
jason@lakedaemon.net, andrew@lunn.ch,
sebastian.hesselbarth@gmail.com,
ezequiel.garcia@free-electrons.com,
linux-arm-kernel@lists.infradead.org, alior@marvell.com,
nadavh@marvell.com, simon.guinot@sequanux.org,
maxime.ripard@free-electrons.com,
boris.brezillon@free-electrons.com, linux@arm.linux.org.uk,
w@1wt.eu, arnd@arndb.de
Subject: Re: [PATCH net-next v2 4/4] net: mvneta: Spread out the TX queues management on all CPUs
Date: Sat, 05 Dec 2015 17:24:37 -0500 (EST) [thread overview]
Message-ID: <20151205.172437.1660871557891874317.davem@davemloft.net> (raw)
In-Reply-To: <CAPv3WKe32dUP0jTkjJkWF=tpJDkR_J3Z5aSR5YT8rJtoMAKyjA@mail.gmail.com>
From: Marcin Wojtas <mw@semihalf.com>
Date: Sat, 5 Dec 2015 20:14:31 +0100
> Hi Gregory,
>
>> @@ -1824,13 +1835,16 @@ error:
>> static int mvneta_tx(struct sk_buff *skb, struct net_device *dev)
>> {
>> struct mvneta_port *pp = netdev_priv(dev);
>> - u16 txq_id = skb_get_queue_mapping(skb);
>> + u16 txq_id = smp_processor_id() % txq_number;
>
> I think it may be ok to bind TXQs to different CPUs, but I don't think
> that replacing skb_get_queue_mapping by in fact smp_processor_id() is
> the best idea. This way you use only 2 TXQs on A385 and 4 TXQs on AXP.
> There are HW mechanisms like WRR or EJP that provide balancing for
> egress, so let's better keep all 8.
Also it is possible for other parts of the stack to set the SKB queue
mapping and you must respect that setting rather than override it.
prev parent reply other threads:[~2015-12-05 22:24 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-04 18:44 [PATCH net-next v2 0/4] mvneta: Introduce RSS support Gregory CLEMENT
2015-12-04 18:44 ` [PATCH net-next v2 1/4] net: mvneta: Make the default queue related for each port Gregory CLEMENT
2015-12-04 18:44 ` [PATCH net-next v2 2/4] net: mvneta: Associate RX queues with each CPU Gregory CLEMENT
2015-12-04 18:44 ` [PATCH net-next v2 3/4] net: mvneta: Add naive RSS support Gregory CLEMENT
2015-12-04 18:45 ` [PATCH net-next v2 4/4] net: mvneta: Spread out the TX queues management on all CPUs Gregory CLEMENT
2015-12-04 19:12 ` Eric Dumazet
2015-12-04 21:30 ` Arnd Bergmann
2015-12-05 19:14 ` Marcin Wojtas
2015-12-05 22:24 ` David Miller [this message]
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