From: Rusty Russell <rusty@rustcorp.com.au>
To: Qin Chuanyu <qinchuanyu@huawei.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
jasowang@redhat.com, KVM list <kvm@vger.kernel.org>
Subject: Re: [PATCH] virtio: make udp more efficient by avoiding indirect desc
Date: Thu, 13 Feb 2014 13:27:44 +1030 [thread overview]
Message-ID: <87a9dvg1nb.fsf@rustcorp.com.au> (raw)
In-Reply-To: <52FA3AAC.2050003@huawei.com>
Qin Chuanyu <qinchuanyu@huawei.com> writes:
> udp packet use 2 buffers at least, one for vnet_hdr and
> one for skb->data.
> we could change the threshold from 2 to 3, so the udp packet
> which data buff only using single desc will gain from this.
> the guest would avoid from allocating memory dynamically.
> the host would avoid from translating indirect desc.
>
> Signed-off-by: Chuanyu Qin <qinchuanyu@huawei.com>
We should really adapt the threshold depending on how full the ring is.
If it's gotten cramped recently, prefer indirect. See linux/average.h.
Such a change would have to be benchmarked carefully though!
Cheers,
Rusty.
prev parent reply other threads:[~2014-02-13 4:40 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-11 14:58 [PATCH] virtio: make udp more efficient by avoiding indirect desc Qin Chuanyu
2014-02-11 15:43 ` Michael S. Tsirkin
2014-02-12 1:51 ` Qin Chuanyu
2014-02-12 8:59 ` Paolo Bonzini
2014-03-03 11:22 ` Qin Chuanyu
2014-02-13 2:57 ` Rusty Russell [this message]
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