From: David Miller <davem@davemloft.net>
To: mst@redhat.com
Cc: vyasevic@redhat.com, alexander.h.duyck@intel.com,
Ian.Campbell@citrix.com, kvm@vger.kernel.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org, edumazet@google.com,
akpm@linux-foundation.org
Subject: Re: [PATCHv3 net-next 0/8] enable/disable zero copy tx dynamically
Date: Fri, 02 Nov 2012 21:31:10 -0400 (EDT) [thread overview]
Message-ID: <20121102.213110.2070365320544608145.davem@davemloft.net> (raw)
In-Reply-To: <cover.1351797353.git.mst@redhat.com>
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Thu, 1 Nov 2012 21:16:17 +0200
>
> tun supports zero copy transmit since 0690899b4d4501b3505be069b9a687e68ccbe15b,
> however you can only enable this mode if you know your workload does not
> trigger heavy guest to host/host to guest traffic - otherwise you
> get a (minor) performance regression.
> This patchset addresses this problem by notifying the owner
> device when callback is invoked because of a data copy.
> This makes it possible to detect whether zero copy is appropriate
> dynamically: we start in zero copy mode, when we detect
> data copied we disable zero copy for a while.
>
> With this patch applied, I get the same performance for
> guest to host and guest to guest both with and without zero copy tx.
Series applied, thanks Michael.
prev parent reply other threads:[~2012-11-03 1:31 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-01 19:16 [PATCHv3 net-next 0/8] enable/disable zero copy tx dynamically Michael S. Tsirkin
2012-11-01 19:16 ` [PATCHv3 net-next 1/8] skb: report completion status for zero copy skbs Michael S. Tsirkin
2012-11-01 19:16 ` [PATCHv3 net-next 2/8] skb: api to report errors " Michael S. Tsirkin
2012-11-01 19:16 ` [PATCHv3 net-next 3/8] tun: report orphan frags errors to zero copy callback Michael S. Tsirkin
2012-11-01 19:16 ` [PATCHv3 net-next 4/8] vhost-net: cleanup macros for DMA status tracking Michael S. Tsirkin
2012-11-01 19:16 ` [PATCHv3 net-next 5/8] vhost: track zero copy failures using DMA length Michael S. Tsirkin
2012-11-01 19:16 ` [PATCHv3 net-next 6/8] vhost: move -net specific code out Michael S. Tsirkin
2012-11-01 19:16 ` [PATCHv3 net-next 7/8] vhost-net: select tx zero copy dynamically Michael S. Tsirkin
2012-11-01 19:16 ` [PATCHv3 net-next 8/8] vhost-net: reduce vq polling on tx zerocopy Michael S. Tsirkin
2012-11-03 1:31 ` David Miller [this message]
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