From mboxrd@z Thu Jan  1 00:00:00 1970
From: Shirley Ma <mashirle@us.ibm.com>
Subject: Re: vhost-net patches
Date: Tue, 27 Oct 2009 09:36:18 -0700
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Cc: Sridhar Samudrala <sri@us.ibm.com>, Shirley Ma <xma@us.ibm.com>,
	David Stevens <dlstevens@us.ibm.com>, kvm@vger.kernel.org,
	sri@linux.vnet.ibm.com, mashirle@linux.vnet.ibm.com
To: "Michael S. Tsirkin" <mst@redhat.com>
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In-Reply-To: <20091027152753.GA4622@redhat.com>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

Hello Michael,

On Tue, 2009-10-27 at 17:27 +0200, Michael S. Tsirkin wrote:
> Possibly GFP_ATOMIC allocations in vring_add_indirect are failing?
> Is there a chance you are tight on guest memory for some reason?
> with vhost, virtio does currently consume a bit more memory than
> with userspace backend.

I did see memory leak on host every time after exiting guest. I don't
know where. Do you see it?

Anyway after I reboot host and restart guest with large memory
allocation, I do see performance improves to 3xxxMb/s, and occasionally
reaches 40xxMb/s. But "queue full" still exists, I can avoid the problem
by increasing send queue size from qemu.

I will apply deferring skb allocation patch on guest to see any
performance gain after your vhost patch.

Thanks
Shirley