From: "Michael S. Tsirkin" <mst@redhat.com>
To: David Miller <davem@davemloft.net>
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: [PATCHv2 net-next 1/8] skb: report completion status for zero copy skbs
Date: Thu, 1 Nov 2012 18:16:11 +0200 [thread overview]
Message-ID: <20121101161611.GA9410@redhat.com> (raw)
In-Reply-To: <20121101.115024.1422610516561380154.davem@davemloft.net>
On Thu, Nov 01, 2012 at 11:50:24AM -0400, David Miller wrote:
> From: "Michael S. Tsirkin" <mst@redhat.com>
> Date: Wed, 31 Oct 2012 12:31:06 +0200
>
> > -void vhost_zerocopy_callback(struct ubuf_info *ubuf)
> > +void vhost_zerocopy_callback(struct ubuf_info *ubuf, int zerocopy_status)
>
> If you're only reporting true/false values, even just for now,
> please use 'bool' for this.
In fact next patch reports -ENOMEM when tun hits OOM so callback can
distinguish between copy (>0 value) and error (<0 value)
and reduce zerocopy more aggressively in case of errors.
The *callback* in vhost-net currently handles all non-zero
values identically, but I am not sure it's the optimal behaviour
so I thought it's worth it to give callbacks the info.
Do you think it's over-engineering, or a good idea?
--
MST
next prev parent reply other threads:[~2012-11-01 16:16 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-31 10:31 [PATCHv2 net-next 0/8] enable/disable zero copy tx dynamically Michael S. Tsirkin
2012-10-31 10:31 ` [PATCHv2 net-next 1/8] skb: report completion status for zero copy skbs Michael S. Tsirkin
2012-11-01 15:50 ` David Miller
[not found] ` <20121101.115024.1422610516561380154.davem@davemloft.net>
2012-11-01 16:16 ` Michael S. Tsirkin [this message]
2012-11-01 16:20 ` David Miller
2012-10-31 10:31 ` [PATCHv2 net-next 2/8] skb: api to report errors " Michael S. Tsirkin
2012-10-31 10:31 ` [PATCHv2 net-next 3/8] tun: report orphan frags errors to zero copy callback Michael S. Tsirkin
2012-10-31 10:31 ` [PATCHv2 net-next 8/8] vhost-net: reduce vq polling on tx zerocopy Michael S. Tsirkin
2012-10-31 10:31 ` [PATCHv2 net-next 4/8] vhost-net: cleanup macros for DMA status tracking Michael S. Tsirkin
2012-10-31 10:31 ` [PATCHv2 net-next 5/8] vhost: track zero copy failures using DMA length Michael S. Tsirkin
2012-10-31 10:31 ` [PATCHv2 net-next 6/8] vhost: move -net specific code out Michael S. Tsirkin
2012-10-31 10:31 ` [PATCHv2 net-next 7/8] vhost-net: select tx zero copy dynamically Michael S. Tsirkin
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