Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752873AbbF3K7h (ORCPT ); Tue, 30 Jun 2015 06:59:37 -0400 Received: from mail-wg0-f48.google.com ([74.125.82.48]:34978 "EHLO mail-wg0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752901AbbF3K73 (ORCPT ); Tue, 30 Jun 2015 06:59:29 -0400 Message-ID: <1435661966.3585.4.camel@gmail.com> Subject: Re: PRREMPT RCU stalls with 9edfbfed3f544a78 ("sched/core: Rework rq->clock update skips") From: Mike Galbraith To: Mark Rutland Cc: "peterz@infradead.org" , linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, "mingo@kernel.org" , paulmck@linux.vnet.ibm.com, Will Deacon Date: Tue, 30 Jun 2015 12:59:26 +0200 In-Reply-To: <20150629173751.GB19863@leverpostej> References: <20150629173751.GB19863@leverpostej> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.11 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1334 Lines: 42 On Mon, 2015-06-29 at 18:37 +0100, Mark Rutland wrote: > Hi, > > Recently (since ~v4.0) I've been seeing new RCU stall warnings when > running hackbench (and cpu-affine cyclictest instances) on > CONFIG_PREEMPT=y kernels, both arm64 and x86_64: FWIW, I'm unable to reproduce on my Haswell box w. preempt config. homer: # grep RCU config.preempt # RCU Subsystem CONFIG_PREEMPT_RCU=y CONFIG_RCU_EXPERT=y CONFIG_SRCU=y # CONFIG_TASKS_RCU is not set CONFIG_RCU_STALL_COMMON=y CONFIG_RCU_USER_QS=y CONFIG_RCU_FANOUT=64 CONFIG_RCU_FANOUT_LEAF=16 # CONFIG_RCU_FAST_NO_HZ is not set # CONFIG_TREE_RCU_TRACE is not set # CONFIG_RCU_BOOST is not set CONFIG_RCU_KTHREAD_PRIO=0 CONFIG_RCU_NOCB_CPU=y CONFIG_RCU_NOCB_CPU_NONE=y # CONFIG_RCU_NOCB_CPU_ZERO is not set # CONFIG_RCU_NOCB_CPU_ALL is not set # CONFIG_RCU_EXPEDITE_BOOT is not set # RCU Debugging # CONFIG_PROVE_RCU is not set # CONFIG_SPARSE_RCU_POINTER is not set # CONFIG_RCU_TORTURE_TEST is not set CONFIG_RCU_CPU_STALL_TIMEOUT=60 # CONFIG_RCU_CPU_STALL_INFO is not set # CONFIG_RCU_TRACE is not set # CONFIG_RCU_EQS_DEBUG is not set -- 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/