From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jesper Dangaard Brouer Subject: Re: dvb usb issues since kernel 4.9 Date: Mon, 8 Jan 2018 23:16:56 +0100 Message-ID: <20180108231656.3bbd1968@redhat.com> References: <20180107090336.03826df2@vento.lan> <20180108074324.3c153189@vento.lan> <20180108223109.66c91554@redhat.com> <20180108214427.GT29822@worktop.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Josef Griebichler , Mauro Carvalho Chehab , Alan Stern , Greg Kroah-Hartman , linux-usb@vger.kernel.org, Eric Dumazet , Rik van Riel , Paolo Abeni , Hannes Frederic Sowa , linux-kernel , netdev , Jonathan Corbet , LMML , David Miller , torvalds@linux-foundation.org To: Peter Zijlstra Return-path: In-Reply-To: <20180108214427.GT29822@worktop.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Mon, 8 Jan 2018 22:44:27 +0100 Peter Zijlstra wrote: > On Mon, Jan 08, 2018 at 10:31:09PM +0100, Jesper Dangaard Brouer wrote: > > I did expected the issue to get worse, when you load the Pi with > > network traffic, as now the softirq time-budget have to be shared > > between networking and USB/DVB. Thus, I guess you are running TCP and > > USB/mpeg2ts on the same CPU (why when you have 4 CPUs?...) > > Isn't networking also over USB on the Pi ? Darn, that is true. Looking at the dmesg output in http://ix.io/DOg: [ 0.405942] usbcore: registered new interface driver smsc95xx [ 5.821104] smsc95xx 1-1.1:1.0 eth0: link up, 100Mbps, full-duplex, lpa 0x45E1 I don't know enough about USB... is it possible to control which CPU handles the individual USB ports, or on some other level (than ports)? -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer