Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751076AbaLCCAJ (ORCPT ); Tue, 2 Dec 2014 21:00:09 -0500 Received: from cn.fujitsu.com ([59.151.112.132]:18974 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1750730AbaLCCAI convert rfc822-to-8bit (ORCPT ); Tue, 2 Dec 2014 21:00:08 -0500 X-IronPort-AV: E=Sophos;i="5.04,848,1406563200"; d="scan'208";a="44386951" Message-ID: <547E6F8C.1060709@cn.fujitsu.com> Date: Wed, 3 Dec 2014 10:03:56 +0800 From: Lai Jiangshan User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100921 Fedora/3.1.4-1.fc14 Thunderbird/3.1.4 MIME-Version: 1.0 To: CC: =?UTF-8?B?RMOibmllbCBGcmFnYQ==?= , Linus Torvalds , Linux Kernel Mailing List Subject: Re: frequent lockups in 3.18rc4 References: <20141126024032.GA13246@redhat.com> <20141126225745.GA30346@redhat.com> <20141127225637.GA24019@redhat.com> <547b8a45.6e608c0a.20f9.1002@mx.google.com> <547bbe36.48548c0a.105c.779c@mx.google.com> <20141201191431.GA17385@linux.vnet.ibm.com> <547D7B05.6080403@cn.fujitsu.com> <547defc3.28568c0a.73eb.1a1e@mx.google.com> In-Reply-To: <547defc3.28568c0a.73eb.1a1e@mx.google.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Originating-IP: [10.167.226.103] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/03/2014 12:58 AM, Dâniel Fraga wrote: > On Tue, 2 Dec 2014 16:40:37 +0800 > Lai Jiangshan wrote: > >> It is needed at lest for testing. >> >> CONFIG_TREE_PREEMPT_RCU=y with CONFIG_PREEMPT=n is needed for testing too. >> >> Please enable them (or enable them under CONFIG_RCU_TRACE=y) > > Lai, sorry but I didn't understand. Do you mean both of them > enabled? Because how can CONFIG_TREE_PREEMPT_RCU be enabled without > CONFIG_PREEMPT ? Sorry, I replied to Paul, and my reply was off-topic, it has nothing related your reports. Sorry again. I think we need two combinations for testing (not mainline, but I think they (combinations) should be enabled for test farms). So I hope Paul enable them (combinations). combination1: CONFIG_TREE_PREEMPT_RCU=n & CONFIG_PREEMPT=y combination2: CONFIG_TREE_PREEMPT_RCU=y & CONFIG_PREEMPT=n The core code should work correctly in these combinations. I agree with Paul that these combinations should not be enabled in production, So my request is: enable these combinations under CONFIG_RCU_TRACE or CONFIG_TREE_RCU_TRACE. For myself, I always edit the Kconfig directly, thus it is not a problem for me. But there is no way for test farms to test these combinations. Thanks, Lai > > If you mean both enabled, I already reported a call trace with > both enabled: > > https://bugzilla.kernel.org/show_bug.cgi?id=85941 > > Please see my previous answer to Linus and Paul too. > > Regarding CONFIG_RCU_TRACE, do you mean > "CONFIG_TREE_RCU_TRACE"? I couldn't find CONFIG_RCU_TRACE. > > Thanks. > -- 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/