Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965480AbeAMJJh convert rfc822-to-8bit (ORCPT + 1 other); Sat, 13 Jan 2018 04:09:37 -0500 Received: from osg.samsung.com ([64.30.133.232]:42364 "EHLO osg.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754593AbeAMJJd (ORCPT ); Sat, 13 Jan 2018 04:09:33 -0500 Date: Sat, 13 Jan 2018 07:09:20 -0200 From: Mauro Carvalho Chehab To: Eric Dumazet Cc: Linus Torvalds , Eric Dumazet , Josef Griebichler , Jesper Dangaard Brouer , Peter Zijlstra , Alan Stern , Greg Kroah-Hartman , USB list , Rik van Riel , Paolo Abeni , Hannes Frederic Sowa , linux-kernel , netdev , Jonathan Corbet , LMML , David Miller , Arnd Bergmann Subject: Re: dvb usb issues since kernel 4.9 Message-ID: <20180113070920.4453eafe@vento.lan> In-Reply-To: <1515793726.3606.1.camel@gmail.com> References: <20180107090336.03826df2@vento.lan> <20180108074324.3c153189@vento.lan> <20180108223109.66c91554@redhat.com> <20180108214427.GT29822@worktop.programming.kicks-ass.net> <20180108231656.3bbd1968@redhat.com> <20180112191343.3083b70e@vento.lan> <1515793726.3606.1.camel@gmail.com> Organization: Samsung X-Mailer: Claws Mail 3.15.1-dirty (GTK+ 2.24.31; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: Em Fri, 12 Jan 2018 13:48:46 -0800 Eric Dumazet escreveu: > On Fri, 2018-01-12 at 19:13 -0200, Mauro Carvalho Chehab wrote: > > > > > > The .config file used to build the Kernel is at: > > https://pastebin.com/wpZghann > > > > Hi Mauro > > Any chance you can try CONFIG_HZ_1000=y, CONFIG_HZ=1000 ? I can do such test to satisfy your curiosity, but that doesn't sound the right fix. See, almost all TV and set top boxes(STB) run Linux nowadays and usually come with ARM cpus designed to "just do their job" (e. g. CPUs with low clocks). There, power consumption is a must. This bug very likely affect those devices, once migrated to Kernel 4.9+. Changing from NO_HZ to HZ=1000 on TV/STB will for sure have bad side effects on those types of devices, increasing power consumption. Not saying that this will be environmentally very bad, as the number of just TV unit sales is at the order of 230 million units per year[1]. [1] https://www.statista.com/statistics/461316/global-tv-unit-sales/ Thanks, Mauro