From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: netdev@vger.kernel.org, yevgenyp@mellanox.com,
ogerlitz@mellanox.com, j.vimal@gmail.com
Subject: Re: [PATCH net-next] mlx4: change TX coalescing defaults
Date: Wed, 07 Nov 2012 15:31:13 -0500 (EST) [thread overview]
Message-ID: <20121107.153113.716743500905191245.davem@davemloft.net> (raw)
In-Reply-To: <1352168442.3140.32.camel@edumazet-glaptop>
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Mon, 05 Nov 2012 18:20:42 -0800
> From: Eric Dumazet <edumazet@google.com>
>
> mlx4 currently uses a too high tx coalescing setting, deferring
> TX completion interrupts by up to 128 us.
>
> With the recent skb_orphan() removal in commit 8112ec3b872,
> performance of a single TCP flow is capped to ~4 Gbps, unless
> we increase tcp_limit_output_bytes.
>
> I suggest using 16 us instead of 128 us, allowing a finer control.
>
> Performance of a single TCP flow is restored to previous levels,
> while keeping TCP small queues fully enabled with default sysctl.
>
> This patch is also a BQL prereq.
>
> Reported-by: Vimalkumar <j.vimal@gmail.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
Applied, thanks Eric.
prev parent reply other threads:[~2012-11-07 20:31 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-06 2:20 [PATCH net-next] mlx4: change TX coalescing defaults Eric Dumazet
2012-11-06 8:04 ` Amir Mellanox
2012-11-06 11:50 ` Eric Dumazet
2012-11-07 15:30 ` Amir Vadai
2012-11-07 16:05 ` Eric Dumazet
2012-11-07 20:31 ` David Miller [this message]
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