Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755522Ab3HWMKQ (ORCPT ); Fri, 23 Aug 2013 08:10:16 -0400 Received: from merlin.infradead.org ([205.233.59.134]:48690 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753260Ab3HWMKO (ORCPT ); Fri, 23 Aug 2013 08:10:14 -0400 Date: Fri, 23 Aug 2013 14:10:04 +0200 From: Peter Zijlstra To: Martin Mokrejs Cc: Theodore Tso , Thomas Gleixner , mingo@redhat.com, LKML , Johannes Berg Subject: Re: [sched_delayed] sched: RT throttling activated Message-ID: <20130823121004.GW31370@twins.programming.kicks-ass.net> References: <521722EE.70209@fold.natur.cuni.cz> <20130823100913.GQ31370@twins.programming.kicks-ass.net> <52173BBD.3050803@fold.natur.cuni.cz> <20130823110254.GU31370@twins.programming.kicks-ass.net> <521748FC.10809@fold.natur.cuni.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <521748FC.10809@fold.natur.cuni.cz> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1817 Lines: 54 On Fri, Aug 23, 2013 at 01:35:24PM +0200, Martin Mokrejs wrote: > # ps -deo pid,cls,cmd | grep -e 'RR \[' -e 'FF \[' This explicitly only lists kernel threads; from your other comment: > The shell/python tasks have 'TS' in place of the FF value in the second column > so I guess they are not requiring realtime responsiveness. I'll assume you actually inspected the other tasks and found none. > 7 FF [migration/0] > 10 FF [watchdog/0] > 11 FF [watchdog/1] > 12 FF [migration/1] > 17 FF [migration/2] > 22 FF [migration/3] The 'migration' threads only look like FIFO threads but they're secretly not and don't count to the limit. The watchdog threads shouldn't run much either. > 2161 FF [irq/50-iwlwifi] Oh a threaded interrupt, I presume you're not using "threadiqrs" since this is the only interrupt thread around and I see a 'request_threaded_irq()' call in drivers/net/wireless/iwlwifi/pcie/trans.c And wow, why would that thing consume that much cpu. Johill, ever seen the iwlwifi interrupt go 'funny' and consume gobs of cpu-time? > > Nope, you get that message once to tell you that we throttle RT tasks. > > I think the message could improved to explain this is a warn ONCE message and > that there is no "[sched_delayed] sched: RT throttling deactivated" counterpart > message to be anticipated. Would something like: sched: [ONCE] RT throttle hit -- inspect system configuration. Be a better message? Also, could you clarify what exact kernel version you're running? I couldn't find it in your previous messages. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/