From: Andrew Lunn <andrew@lunn•ch>
To: Gerhard Engleder <gerhard@engleder-embedded•com>
Cc: netdev@vger•kernel.org, davem@davemloft•net, kuba@kernel•org,
edumazet@google•com, pabeni@redhat•com
Subject: Re: [PATCH net-next v2 3/4] tsnep: Throttle interrupts
Date: Wed, 30 Nov 2022 23:53:34 +0100 [thread overview]
Message-ID: <Y4fe7i+UypsTbWgQ@lunn.ch> (raw)
In-Reply-To: <20221130193708.70747-4-gerhard@engleder-embedded.com>
On Wed, Nov 30, 2022 at 08:37:07PM +0100, Gerhard Engleder wrote:
> Without interrupt throttling, iperf server mode generates a CPU load of
> 100% (A53 1.2GHz). Also the throughput suffers with less than 900Mbit/s
> on a 1Gbit/s link. The reason is a high interrupt load with interrupts
> every ~20us.
>
> Reduce interrupt load by throttling of interrupts. Interrupt delay
> default is 64us. For iperf server mode the CPU load is significantly
> reduced to ~20% and the throughput reaches the maximum of 941MBit/s.
> Interrupts are generated every ~140us.
>
> RX and TX coalesce can be configured with ethtool. RX coalesce has
> priority over TX coalesce if the same interrupt is used.
>
> Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded•com>
Reviewed-by: Andrew Lunn <andrew@lunn•ch>
Andrew
next prev parent reply other threads:[~2022-11-30 22:53 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-30 19:37 [PATCH net-next v2 0/4] tsnep: Throttle interrupts, RX buffer allocation and ethtool_get_channels() Gerhard Engleder
2022-11-30 19:37 ` [PATCH net-next v2 1/4] tsnep: Consistent naming of struct net_device Gerhard Engleder
2022-11-30 22:39 ` Andrew Lunn
2022-11-30 19:37 ` [PATCH net-next v2 2/4] tsnep: Add ethtool::get_channels support Gerhard Engleder
2022-11-30 22:39 ` Andrew Lunn
2022-11-30 19:37 ` [PATCH net-next v2 3/4] tsnep: Throttle interrupts Gerhard Engleder
2022-11-30 22:53 ` Andrew Lunn [this message]
2022-11-30 19:37 ` [PATCH net-next v2 4/4] tsnep: Rework RX buffer allocation Gerhard Engleder
2022-12-02 11:20 ` [PATCH net-next v2 0/4] tsnep: Throttle interrupts, RX buffer allocation and ethtool_get_channels() patchwork-bot+netdevbpf
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