* Re: [PATCH net-next] mlx4: change TX coalescing defaults
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 20:31 ` David Miller
2 siblings, 1 reply; 6+ messages in thread
From: Amir Mellanox @ 2012-11-06 8:04 UTC (permalink / raw)
To: Eric Dumazet
Cc: David Miller, netdev, Yevgeny Petrilin, Or Gerlitz, Vimalkumar,
amirv
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 <eric.dumazet@gmail.com> wrote:
> 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>
> Cc: Yevgeny Petrilin <yevgenyp@mellanox.com>
> Cc: Or Gerlitz <ogerlitz@mellanox.com>
> ---
> 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
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH net-next] mlx4: change TX coalescing defaults
2012-11-06 8:04 ` Amir Mellanox
@ 2012-11-06 11:50 ` Eric Dumazet
0 siblings, 0 replies; 6+ messages in thread
From: Eric Dumazet @ 2012-11-06 11:50 UTC (permalink / raw)
To: Amir Mellanox
Cc: David Miller, netdev, Yevgeny Petrilin, Or Gerlitz, Vimalkumar,
amirv
On Tue, 2012-11-06 at 10:04 +0200, Amir Mellanox wrote:
> 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
Oh right, it seems I was not looking for right verbs or changelog
keywords ;)
Then I suspect my patch will help to keep inflight BQL counter lower and
reduce latencies.
Thanks
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net-next] mlx4: change TX coalescing defaults
2012-11-06 2:20 [PATCH net-next] mlx4: change TX coalescing defaults Eric Dumazet
2012-11-06 8:04 ` Amir Mellanox
@ 2012-11-07 15:30 ` Amir Vadai
2012-11-07 16:05 ` Eric Dumazet
2012-11-07 20:31 ` David Miller
2 siblings, 1 reply; 6+ messages in thread
From: Amir Vadai @ 2012-11-07 15:30 UTC (permalink / raw)
To: Eric Dumazet
Cc: David Miller, netdev, Yevgeny Petrilin, Or Gerlitz, Vimalkumar
Acked.
BTW, a mail will be sent - I'm replacing Yevgeny Petrilin as mlx4_en maintainer.
(sorry for the previous non plain text mail)
Amir
On Tue, Nov 6, 2012 at 4:20 AM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
>
> 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>
> Cc: Yevgeny Petrilin <yevgenyp@mellanox.com>
> Cc: Or Gerlitz <ogerlitz@mellanox.com>
> ---
> 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
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH net-next] mlx4: change TX coalescing defaults
2012-11-07 15:30 ` Amir Vadai
@ 2012-11-07 16:05 ` Eric Dumazet
0 siblings, 0 replies; 6+ messages in thread
From: Eric Dumazet @ 2012-11-07 16:05 UTC (permalink / raw)
To: Amir Vadai; +Cc: David Miller, netdev, Yevgeny Petrilin, Or Gerlitz, Vimalkumar
On Wed, 2012-11-07 at 17:30 +0200, Amir Vadai wrote:
> Acked.
>
> BTW, a mail will be sent - I'm replacing Yevgeny Petrilin as mlx4_en maintainer.
>
OK, thanks.
BTW proper way to Ack a patch so that its automatically taken into
account by tools is to use :
Acked-by: Amir Vadai <amirv@mellanox.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net-next] mlx4: change TX coalescing defaults
2012-11-06 2:20 [PATCH net-next] mlx4: change TX coalescing defaults Eric Dumazet
2012-11-06 8:04 ` Amir Mellanox
2012-11-07 15:30 ` Amir Vadai
@ 2012-11-07 20:31 ` David Miller
2 siblings, 0 replies; 6+ messages in thread
From: David Miller @ 2012-11-07 20:31 UTC (permalink / raw)
To: eric.dumazet; +Cc: netdev, yevgenyp, ogerlitz, j.vimal
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.
^ permalink raw reply [flat|nested] 6+ messages in thread