From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755397AbcAMR6s (ORCPT ); Wed, 13 Jan 2016 12:58:48 -0500 Received: from www.linutronix.de ([62.245.132.108]:51585 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755005AbcAMR6r (ORCPT ); Wed, 13 Jan 2016 12:58:47 -0500 Date: Wed, 13 Jan 2016 18:58:45 +0100 From: Sebastian Andrzej Siewior To: Mike Galbraith Cc: Clark Williams , Thomas Gleixner , LKML , linux-rt-users , Steven Rostedt Subject: Re: [ANNOUNCE] 4.4-rc6-rt1 Message-ID: <20160113175845.GK29964@linutronix.de> References: <20151223225755.GA21121@linutronix.de> <20151231102441.581ce1e1@sluggy.hsv.redhat.com> <1451632781.9800.22.camel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1451632781.9800.22.camel@gmail.com> X-Key-Id: 2A8CF5D1 X-Key-Fingerprint: 6425 4695 FFF0 AA44 66CC 19E6 7B96 E816 2A8C F5D1 User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Mike Galbraith | 2016-01-01 08:19:41 [+0100]: >> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND >> 3 root -2 0 0 0 0 S 37.3 0.0 307:52.44 ksoftirqd/0 >> 32 root -2 0 0 0 0 S 37.3 0.0 308:08.72 ksoftirqd/2 >> 42 root -2 0 0 0 0 R 37.3 0.0 308:32.84 ksoftirqd/3 >> 22 root -2 0 0 0 0 S 26.9 0.0 222:29.82 ksoftirqd/1 >> 1 root 20 0 46628 6980 4976 S 1.3 0.2 0:13.98 systemd >> 22358 williams 20 0 159980 4552 3780 R 1.0 0.1 0:00.39 top > >Heh, I didn't notice immediately because I throttle nohz, am seeing >only tiny utilization (but nohz idle isn't working). With throttle >patch removed, box is screaming, expires=4294990471 pokes eyeball. This is due to NO_HZ as far as I can tell. My AMD A10 in idle mode has 0.7% utilisation of ksoftirqd/ with CONFIG_HZ_PERIODIC and with CONFIG_NO_HZ_FULL it shows about 25% on all CPU threads. Sebastian