From mboxrd@z Thu Jan 1 00:00:00 1970 From: Amir Mellanox Subject: Re: [PATCH net-next] mlx4: change TX coalescing defaults Date: Tue, 6 Nov 2012 10:04:46 +0200 Message-ID: References: <1352168442.3140.32.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: David Miller , netdev , Yevgeny Petrilin , Or Gerlitz , Vimalkumar , amirv@mellanox.com To: Eric Dumazet Return-path: Received: from mail-ee0-f46.google.com ([74.125.83.46]:42343 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753667Ab2KFIEr (ORCPT ); Tue, 6 Nov 2012 03:04:47 -0500 Received: by mail-ee0-f46.google.com with SMTP id b15so73923eek.19 for ; Tue, 06 Nov 2012 00:04:46 -0800 (PST) In-Reply-To: <1352168442.3140.32.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: Eric Hi, I will check and review your patch and return to you ASAP. Regarding BQL, the driver has it over half a year now, In commit: 5b263f5374ea70daa61ed9f5cc5d8f4ac236efbd Amir. On Tue, Nov 6, 2012 at 4:20 AM, Eric Dumazet wrote: > From: Eric Dumazet > > 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 > Signed-off-by: Eric Dumazet > Cc: Yevgeny Petrilin > Cc: Or Gerlitz > --- > By the way, is BQL addition planned for this driver ? > > drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 2 +- > drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c > index edd9cb8..2b23ca2 100644 > --- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c > +++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c > @@ -870,7 +870,7 @@ static void mlx4_en_set_default_moderation(struct mlx4_en_priv *priv) > /* If we haven't received a specific coalescing setting > * (module param), we set the moderation parameters as follows: > * - moder_cnt is set to the number of mtu sized packets to > - * satisfy our coelsing target. > + * satisfy our coalescing target. > * - moder_time is set to a fixed value. > */ > priv->rx_frames = MLX4_EN_RX_COAL_TARGET; > diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h > index 9d27e42..8a5e70d 100644 > --- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h > +++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h > @@ -126,7 +126,7 @@ enum { > #define MLX4_EN_RX_COAL_TIME 0x10 > > #define MLX4_EN_TX_COAL_PKTS 16 > -#define MLX4_EN_TX_COAL_TIME 0x80 > +#define MLX4_EN_TX_COAL_TIME 0x10 > > #define MLX4_EN_RX_RATE_LOW 400000 > #define MLX4_EN_RX_COAL_TIME_LOW 0 > > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html