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From: David Miller <davem@davemloft.net>
To: jasowang@redhat.com
Cc: mst@redhat.com, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	eric.dumazet@gmail.com, brouer@redhat.com
Subject: Re: [PATCH net-next V2] tun: introduce tx skb ring
Date: Thu, 16 Jun 2016 17:01:31 -0700 (PDT)	[thread overview]
Message-ID: <20160616.170131.1753206993488742551.davem@davemloft.net> (raw)
In-Reply-To: <1465979897-4445-1-git-send-email-jasowang@redhat.com>

From: Jason Wang <jasowang@redhat.com>
Date: Wed, 15 Jun 2016 16:38:17 +0800

> We used to queue tx packets in sk_receive_queue, this is less
> efficient since it requires spinlocks to synchronize between producer
> and consumer.
> 
> This patch tries to address this by:
> 
> - introduce a new mode which will be only enabled with IFF_TX_ARRAY
>   set and switch from sk_receive_queue to a fixed size of skb
>   array with 256 entries in this mode.
> - introduce a new proto_ops peek_len which was used for peeking the
>   skb length.
> - implement a tun version of peek_len for vhost_net to use and convert
>   vhost_net to use peek_len if possible.
> 
> Pktgen test shows about 18% improvement on guest receiving pps for small
> buffers:
> 
> Before: ~1220000pps
> After : ~1440000pps
> 
> The reason why I stick to new mode is because:
> 
> - though resize is supported by skb array, in multiqueue mode, it's
>   not easy to recover from a partial success of queue resizing.
> - tx_queue_len is a user visible feature.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Michael, can you please review this, especially as this is the first
user of your new infrastructure :-)

WARNING: multiple messages have this Message-ID (diff)
From: David Miller <davem@davemloft.net>
To: jasowang@redhat.com
Cc: kvm@vger.kernel.org, eric.dumazet@gmail.com, mst@redhat.com,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	virtualization@lists.linux-foundation.org, brouer@redhat.com
Subject: Re: [PATCH net-next V2] tun: introduce tx skb ring
Date: Thu, 16 Jun 2016 17:01:31 -0700 (PDT)	[thread overview]
Message-ID: <20160616.170131.1753206993488742551.davem@davemloft.net> (raw)
In-Reply-To: <1465979897-4445-1-git-send-email-jasowang@redhat.com>

From: Jason Wang <jasowang@redhat.com>
Date: Wed, 15 Jun 2016 16:38:17 +0800

> We used to queue tx packets in sk_receive_queue, this is less
> efficient since it requires spinlocks to synchronize between producer
> and consumer.
> 
> This patch tries to address this by:
> 
> - introduce a new mode which will be only enabled with IFF_TX_ARRAY
>   set and switch from sk_receive_queue to a fixed size of skb
>   array with 256 entries in this mode.
> - introduce a new proto_ops peek_len which was used for peeking the
>   skb length.
> - implement a tun version of peek_len for vhost_net to use and convert
>   vhost_net to use peek_len if possible.
> 
> Pktgen test shows about 18% improvement on guest receiving pps for small
> buffers:
> 
> Before: ~1220000pps
> After : ~1440000pps
> 
> The reason why I stick to new mode is because:
> 
> - though resize is supported by skb array, in multiqueue mode, it's
>   not easy to recover from a partial success of queue resizing.
> - tx_queue_len is a user visible feature.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Michael, can you please review this, especially as this is the first
user of your new infrastructure :-)

  parent reply	other threads:[~2016-06-17  0:01 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-15  8:38 [PATCH net-next V2] tun: introduce tx skb ring Jason Wang
2016-06-15 10:34 ` kbuild test robot
2016-06-15 10:34 ` kbuild test robot
2016-06-15 11:52 ` Jamal Hadi Salim
2016-06-15 11:55   ` Jamal Hadi Salim
2016-06-16  7:08     ` Jason Wang
2016-06-15 11:55   ` Jamal Hadi Salim
2016-06-15 11:52 ` Jamal Hadi Salim
2016-06-17  0:01 ` David Miller [this message]
2016-06-17  0:01   ` David Miller
2016-06-17  0:41 ` Michael S. Tsirkin
2016-06-17  0:41 ` Michael S. Tsirkin
2016-06-17  7:22   ` Jason Wang
2016-06-17  7:22   ` Jason Wang
2016-06-22 18:18   ` Michael S. Tsirkin
2016-06-22 18:18     ` Michael S. Tsirkin
2016-06-23  5:14     ` Jason Wang
2016-06-23  5:14       ` Jason Wang
2016-06-28  7:09       ` Michael S. Tsirkin
2016-06-28  7:09         ` Michael S. Tsirkin
2016-06-30  1:50         ` Jason Wang
2016-06-30  1:50           ` Jason Wang
2016-06-15  8:38 Jason Wang

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