From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S970418AbdDTPOW (ORCPT ); Thu, 20 Apr 2017 11:14:22 -0400 Received: from mail-yw0-f175.google.com ([209.85.161.175]:33328 "EHLO mail-yw0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S970401AbdDTPOU (ORCPT ); Thu, 20 Apr 2017 11:14:20 -0400 MIME-Version: 1.0 In-Reply-To: <20170418170553.026838125@linutronix.de> References: <20170418170442.665445272@linutronix.de> <20170418170553.026838125@linutronix.de> From: Mathieu Poirier Date: Thu, 20 Apr 2017 09:14:13 -0600 Message-ID: Subject: Re: [patch V2 08/24] hwtracing/coresight-etm3x: Use cpuhp_setup_state_nocalls_cpuslocked() To: Thomas Gleixner Cc: LKML , Peter Zijlstra , Ingo Molnar , Steven Rostedt , Sebastian Siewior , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 18 April 2017 at 11:04, Thomas Gleixner wrote: > From: Sebastian Andrzej Siewior > > etm_probe() holds get_online_cpus() while invoking > cpuhp_setup_state_nocalls(). > > cpuhp_setup_state_nocalls() invokes get_online_cpus() as well. This is > correct, but prevents the conversion of the hotplug locking to a percpu > rwsem. > > Use cpuhp_setup_state_nocalls_cpuslocked() to avoid the nested call. > > Signed-off-by: Sebastian Andrzej Siewior > Signed-off-by: Thomas Gleixner > Cc: Mathieu Poirier > Cc: linux-arm-kernel@lists.infradead.org > > --- > drivers/hwtracing/coresight/coresight-etm3x.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > --- a/drivers/hwtracing/coresight/coresight-etm3x.c > +++ b/drivers/hwtracing/coresight/coresight-etm3x.c > @@ -803,12 +803,12 @@ static int etm_probe(struct amba_device > dev_err(dev, "ETM arch init failed\n"); > > if (!etm_count++) { > - cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING, > - "arm/coresight:starting", > - etm_starting_cpu, etm_dying_cpu); > - ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, > - "arm/coresight:online", > - etm_online_cpu, NULL); > + cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ARM_CORESIGHT_STARTING, > + "arm/coresight:starting", > + etm_starting_cpu, etm_dying_cpu); > + ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN, > + "arm/coresight:online", > + etm_online_cpu, NULL); > if (ret < 0) > goto err_arch_supported; > hp_online = ret; > Acked-by: Mathieu Poirier From mboxrd@z Thu Jan 1 00:00:00 1970 From: mathieu.poirier@linaro.org (Mathieu Poirier) Date: Thu, 20 Apr 2017 09:14:13 -0600 Subject: [patch V2 08/24] hwtracing/coresight-etm3x: Use cpuhp_setup_state_nocalls_cpuslocked() In-Reply-To: <20170418170553.026838125@linutronix.de> References: <20170418170442.665445272@linutronix.de> <20170418170553.026838125@linutronix.de> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 18 April 2017 at 11:04, Thomas Gleixner wrote: > From: Sebastian Andrzej Siewior > > etm_probe() holds get_online_cpus() while invoking > cpuhp_setup_state_nocalls(). > > cpuhp_setup_state_nocalls() invokes get_online_cpus() as well. This is > correct, but prevents the conversion of the hotplug locking to a percpu > rwsem. > > Use cpuhp_setup_state_nocalls_cpuslocked() to avoid the nested call. > > Signed-off-by: Sebastian Andrzej Siewior > Signed-off-by: Thomas Gleixner > Cc: Mathieu Poirier > Cc: linux-arm-kernel at lists.infradead.org > > --- > drivers/hwtracing/coresight/coresight-etm3x.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > --- a/drivers/hwtracing/coresight/coresight-etm3x.c > +++ b/drivers/hwtracing/coresight/coresight-etm3x.c > @@ -803,12 +803,12 @@ static int etm_probe(struct amba_device > dev_err(dev, "ETM arch init failed\n"); > > if (!etm_count++) { > - cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING, > - "arm/coresight:starting", > - etm_starting_cpu, etm_dying_cpu); > - ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, > - "arm/coresight:online", > - etm_online_cpu, NULL); > + cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ARM_CORESIGHT_STARTING, > + "arm/coresight:starting", > + etm_starting_cpu, etm_dying_cpu); > + ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN, > + "arm/coresight:online", > + etm_online_cpu, NULL); > if (ret < 0) > goto err_arch_supported; > hp_online = ret; > Acked-by: Mathieu Poirier