Re: [PATCH net-next 7/8] vhost_net: try batch dequing from skb array

From: "Michael S. Tsirkin" <mst@redhat.com>
To: Jason Wang <jasowang@redhat.com>
Cc: Pankaj Gupta <pagupta@redhat.com>,
	kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next 7/8] vhost_net: try batch dequing from skb array
Date: Thu, 30 Mar 2017 00:47:33 +0300	[thread overview]
Message-ID: <20170330004654-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <cea3d380-389e-d258-915a-3d4f60232535@redhat.com>

On Wed, Mar 29, 2017 at 06:53:27PM +0800, Jason Wang wrote:
> 
> 
> On 2017年03月29日 18:46, Pankaj Gupta wrote:
> > Hi Jason,
> > 
> > > On 2017年03月23日 13:34, Jason Wang wrote:
> > > > 
> > > > > > +{
> > > > > > +    if (rvq->rh != rvq->rt)
> > > > > > +        goto out;
> > > > > > +
> > > > > > +    rvq->rh = rvq->rt = 0;
> > > > > > +    rvq->rt = skb_array_consume_batched_bh(rvq->rx_array, rvq->rxq,
> > > > > > +                        VHOST_RX_BATCH);
> > > > > A comment explaining why is is -bh would be helpful.
> > > > Ok.
> > > > 
> > > > Thanks
> > > Rethink about this. It looks like -bh is not needed in this case since
> > > no consumer run in bh.
> > In that case do we need other variants of "ptr_ring_consume_batched_*()" functions.
> > Are we planning to use them in future?
> 
> I think we'd better keep them, since it serves as helpers. You can see that
> not all the helpers in ptr_ring has real users, but they were prepared for
> the future use.
> 
> Thanks

Makes sense for basic building blocks but I'm not sure we
need to do it for all APIs.

> > 
> > > Thanks
> > > 