From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: Aw: Re: dvb usb issues since kernel 4.9 From: Jesper Dangaard Brouer Message-Id: <20180108223109.66c91554@redhat.com> Date: Mon, 8 Jan 2018 22:31:09 +0100 To: Josef Griebichler Cc: 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 , Peter Zijlstra , David Miller , torvalds@linux-foundation.org List-ID: T24gTW9uLCA4IEphbiAyMDE4IDE3OjI2OjEwICswMTAwCiJKb3NlZiBHcmllYmljaGxlciIgPGdy aWViaWNobGVyLmpvc2VmQGdteC5hdD4gd3JvdGU6Cgo+IEkgdHJpZWQgeW91ciBtZW50aW9uZWQg cGF0Y2ggYnV0IHVuZm9ydHVuYXRlbHkgbm8gcmVhbCBpbXByb3ZlbWVudCBmb3IgbWUuCj4gZG1l c2cgaHR0cDovL2l4LmlvL0RPZwo+IHR2aGVhZGVuZCBzZXJ2aWNlIGxvZyBodHRwOi8vaXguaW8v RE9pCj4KPiBFcnJvcnMgZHVyaW5nIHJlY29yZGluZyBhcmUgc3RpbGwgdGhlcmUuCgpBcmUgeW91 IF9hbHNvXyByZWNvcmRpbmcgdGhlIHN0cmVhbSBvbiB0aGUgUmFzcGJlcnJ5IFBpPwoKSXQgc2Vl bXMgdG8gbWUsIHRoYXQgeW91IGFyZSBleHBlY3RpbmcgdG9vIG11Y2ggZnJvbSB0aGlzIHNtYWxs IGRldmljZS4KCj4gRXJyb3JzIGluY3JlYXNlIGlmIHRoZXJlIGlzIGFkZGl0aW9uYWwgdGNwIGxv YWQgb24gcmFzcGJlcnJ5LgoKSSBkaWQgZXhwZWN0ZWQgdGhlIGlzc3VlIHRvIGdldCB3b3JzZSwg d2hlbiB5b3UgbG9hZCB0aGUgUGkgd2l0aApuZXR3b3JrIHRyYWZmaWMsIGFzIG5vdyB0aGUgc29m dGlycSB0aW1lLWJ1ZGdldCBoYXZlIHRvIGJlIHNoYXJlZApiZXR3ZWVuIG5ldHdvcmtpbmcgYW5k IFVTQi9EVkIuIFRodXMsIEkgZ3Vlc3MgeW91IGFyZSBydW5uaW5nIFRDUCBhbmQKVVNCL21wZWcy dHMgb24gdGhlIHNhbWUgQ1BVICh3aHkgd2hlbiB5b3UgaGF2ZSA0IENQVXM/Li4uKQoKSWYgeW91 IGV4cGVjdC93YW50IHRvIGdldCBzdGFibGUgcGVyZm9ybWFuY2Ugb3V0IG9mIHN1Y2ggYSBzbWFs bCBib3gsCnRoZW4geW91IChvciBMaWJyZUVMRUMpIG5lZWQgdG8gdHVuZSB0aGUgYm94IGZvciB0 aGlzIHVzYWdlLiAgQW5kIGl0CmRvZXMgbm90IGhhdmUgdG8gYmUgdGhhdCBjb21wbGljYXRlZC4g IEZpcnN0IHN0ZXAgaXMgdG8gbW92ZSBJUlEKaGFuZGxpbmcgZm9yIHRoZSBOSUMgdG8gYW5vdGhl ciBDUFUgYW5kIHRoYW4gdGhlIFVTQiBwb3J0IGhhbmRsaW5nIHRoZQpEVkIgc2lnbmFsICgvcHJv Yy9pcnEvKi9zbXBfYWZmaW5pdHlfbGlzdCkuICBBbmQgdGhlbiBwaW4gdGhlCnVzZXJzcGFjZSBw cm9jZXNzICh0YXNrc2V0KSB0byBhbm90aGVyIENQVSB0aGFuIHRoZSBvbmUgaGFuZGxpbmcKVVNC LXNvZnRpcnEuCgo+IFVuZm9ydHVuYXRlbHkgdGhlcmUncyBubyB1c2Jtb24gb3IgdHNoYXJrIG9u IGxpYnJlZWxlYyBzbyBJIGNhbid0Cj4gcHJvdmlkZSBmdXJ0aGVyIGxvZ3MuCgpEbyB5b3UgaGF2 ZSBwZXJmIG9yIHRyYWNlLWNtZCBvbiB0aGUgYm94PyAgTWF5YmUgd2UgY291bGQgY29tZSB1cCB3 aXRoCnNvbWUga2VybmVsIGZ1bmN0aW9ucyB0byB0cmFjZSwgdG8gbWVhc3VyZS9zaG93IHRoZSBs YXRlbmN5IHNwaWtlcz8K From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:56084 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755097AbeAHVbt (ORCPT ); Mon, 8 Jan 2018 16:31:49 -0500 Date: Mon, 8 Jan 2018 22:31:09 +0100 From: Jesper Dangaard Brouer To: "Josef Griebichler" Cc: "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 , "Peter Zijlstra" , "David Miller" , torvalds@linux-foundation.org Subject: Re: dvb usb issues since kernel 4.9 Message-ID: <20180108223109.66c91554@redhat.com> In-Reply-To: References: <20180107090336.03826df2@vento.lan> <20180108074324.3c153189@vento.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On Mon, 8 Jan 2018 17:26:10 +0100 "Josef Griebichler" wrote: > I tried your mentioned patch but unfortunately no real improvement for me. > dmesg http://ix.io/DOg > tvheadend service log http://ix.io/DOi > > Errors during recording are still there. Are you _also_ recording the stream on the Raspberry Pi? It seems to me, that you are expecting too much from this small device. > Errors increase if there is additional tcp load on raspberry. 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?...) If you expect/want to get stable performance out of such a small box, then you (or LibreELEC) need to tune the box for this usage. And it does not have to be that complicated. First step is to move IRQ handling for the NIC to another CPU and than the USB port handling the DVB signal (/proc/irq/*/smp_affinity_list). And then pin the userspace process (taskset) to another CPU than the one handling USB-softirq. > Unfortunately there's no usbmon or tshark on libreelec so I can't > provide further logs. Do you have perf or trace-cmd on the box? Maybe we could come up with some kernel functions to trace, to measure/show the latency spikes? -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer