From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765049AbdEZPmp (ORCPT ); Fri, 26 May 2017 11:42:45 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:33434 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S940765AbdEZPmm (ORCPT ); Fri, 26 May 2017 11:42:42 -0400 Date: Fri, 26 May 2017 08:42:36 -0700 From: "Paul E. McKenney" To: Leonard Crestez Cc: Shawn Guo , Fabio Estevam , Dong Aisheng , linux-arm-kernel@lists.infradead.org, Matt Fleming , Octavian Purdila , Stephen Rothwell , linux-kernel@vger.kernel.org Subject: Re: [PATCH] ARM: imx_v6_v7_defconfig: Explicitly restore CONFIG_DEBUG_FS Reply-To: paulmck@linux.vnet.ibm.com References: <49b2579b9ad2e5ce0a7c4b163dffb5a885ac7dae.1495797565.git.leonard.crestez@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49b2579b9ad2e5ce0a7c4b163dffb5a885ac7dae.1495797565.git.leonard.crestez@nxp.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 17052615-0024-0000-0000-0000027C9D97 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007121; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000212; SDB=6.00865889; UDB=6.00430046; IPR=6.00645751; BA=6.00005375; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015596; XFM=3.00000015; UTC=2017-05-26 15:42:39 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17052615-0025-0000-0000-000044258848 Message-Id: <20170526154236.GY3956@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-05-26_10:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1705260281 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 26, 2017 at 02:26:06PM +0300, Leonard Crestez wrote: > This option was removed by "make savedefconfig" in > commit c5054a98bce4 ("ARM: imx_v6_v7_defconfig: Select SMSC_PHY") > > This happened because CONFIG_DEBUG_FS was implicitly selected by > CONFIG_TREE_RCU_TRACE which defaulted to true because CONFIG_RCU_TRACE > was enabled by default by commit 961518259b3b ("rcu: Enable RCU > tracepoints by default to aid in debugging") > > Recently however CONFIG_RCU_TRACE was completely removed by > commit 6e74c237c410 ("rcu: Remove debugfs tracing") CONFIG_RCU_TRACE is still very much alive in its new home at kernel/rcu/Kconfig.debug: config RCU_TRACE bool "Enable tracing for RCU" depends on DEBUG_KERNEL default y if TREE_RCU select TRACE_CLOCK help This option enables additional tracepoints for ftrace-style event tracing. Say Y here if you want to enable RCU tracing Say N if you are unsure. That said, I need to make it default to "y" if PREEMPT_RCU as well as the current TREE_RCU. Would that help? Thanx, Paul > The result is that imx_v6_v7_defconfig no longer includes DEBUG_FS on > linux-next since next-20170517. This is bad, DEBUG_FS is extremely > useful for kernel introspection and testing. > > Signed-off-by: Leonard Crestez > --- > > Patch is against next-20170526. Applying it to shawnguo/imx/defconfig > and cycling via savedefconfig makes this diff go away. > > Alternatively maybe DEBUG_FS itself could be made "default y if DEBUG_KERNEL" > or similar? > > arch/arm/configs/imx_v6_v7_defconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm/configs/imx_v6_v7_defconfig b/arch/arm/configs/imx_v6_v7_defconfig > index bf1e7e3..51ca814 100644 > --- a/arch/arm/configs/imx_v6_v7_defconfig > +++ b/arch/arm/configs/imx_v6_v7_defconfig > @@ -381,6 +381,7 @@ CONFIG_NLS_ISO8859_1=y > CONFIG_NLS_ISO8859_15=m > CONFIG_NLS_UTF8=y > CONFIG_PRINTK_TIME=y > +CONFIG_DEBUG_FS=y > CONFIG_MAGIC_SYSRQ=y > # CONFIG_SCHED_DEBUG is not set > CONFIG_PROVE_LOCKING=y > -- > 2.7.4 >