From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jesper Dangaard Brouer Subject: Re: [PATCH net-next] tuntap: introduce tx skb ring Date: Wed, 18 May 2016 10:16:31 +0200 Message-ID: <20160518101631.368e3447@redhat.com> References: <1463361421-4397-1-git-send-email-jasowang@redhat.com> <20160516070012-mutt-send-email-mst@redhat.com> <57397C2B.7000603@redhat.com> <20160516105434-mutt-send-email-mst@redhat.com> <573A761D.8080909@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: brouer@redhat.com, "Michael S. Tsirkin" , davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Jason Wang Return-path: In-Reply-To: <573A761D.8080909@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, 17 May 2016 09:38:37 +0800 Jason Wang wrote: > >> And if tx_queue_length is not power of 2, > >> we probably need modulus to calculate the capacity. > > Is that really that important for speed? > > Not sure, I can test. In my experience, yes, adding a modulus does affect performance. > > If yes, round it up to next power of two. > > Right, this sounds a good solution. Good idea. -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat Author of http://www.iptv-analyzer.org LinkedIn: http://www.linkedin.com/in/brouer