From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sudeep Holla Subject: Re: How to remove warn msg "cache: parent cpui should not be sleeping" i=1, 2, 3... Date: Wed, 21 Dec 2016 16:54:22 +0000 Message-ID: References: <20161221193703.6eac880c@xhacker> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from foss.arm.com ([217.140.101.70]:33092 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757871AbcLUQy1 (ORCPT ); Wed, 21 Dec 2016 11:54:27 -0500 In-Reply-To: <20161221193703.6eac880c@xhacker> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Jisheng Zhang , linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, "Rafael J. Wysocki" Cc: Sudeep Holla On 21/12/16 11:37, Jisheng Zhang wrote: > Hi all, > > I'm not sure this is a bug, when wake up from s2ram, I could get something > like: > > [ 313.271464] Enabling non-boot CPUs ... > [ 313.271551] CPU1: Booted secondary processor > [ 313.271556] Detected VIPT I-cache on CPU1 > [ 313.301378] cache: parent cpu1 should not be sleeping > [ 313.301504] CPU1 is up > [ 313.301582] CPU2: Booted secondary processor > [ 313.301585] Detected VIPT I-cache on CPU2 > [ 313.331485] cache: parent cpu2 should not be sleeping > [ 313.331605] CPU2 is up > [ 313.331683] CPU3: Booted secondary processor > [ 313.331686] Detected VIPT I-cache on CPU3 > [ 313.361599] cache: parent cpu3 should not be sleeping > [ 313.361719] CPU3 is up > > This is because we call cpu_device_create() when secondary cpu is brought > online, the cpu_cache device's parent device: cpu device isn't already > resumed, all device resume will resume after secondary cores are brought > up. > > What's the elegant solution to remove this warning msg? > It is not a serious warning as you can see a comment in the code: "/* * This is a fib. But we'll allow new children to be added below * a resumed device, even if the device hasn't been completed yet. */" But if we think it needs to be removed, I have something like below in my mind. I am not sure if this is hacky or not(completely untested, not even compiled). Regards, Sudeep -->8 diff --git i/drivers/base/cpu.c w/drivers/base/cpu.c index 4c28e1a09786..2a5c04377adf 100644 --- i/drivers/base/cpu.c +++ w/drivers/base/cpu.c @@ -344,6 +344,14 @@ static int cpu_uevent(struct device *dev, struct kobj_uevent_env *env) } #endif +static int cpu_dev_pm_unset_is_prepared(unsigned int cpu) +{ + struct device *cpu_dev = get_cpu_device(cpu); + + if(cpu_dev) + cpu_dev->power.is_prepared = false; + return 0; +} /* * register_cpu - Setup a sysfs device for a CPU. * @cpu - cpu->hotpluggable field set to 1 will generate a control file in @@ -377,7 +385,9 @@ int register_cpu(struct cpu *cpu, int num) per_cpu(cpu_sys_devices, num) = &cpu->dev; register_cpu_under_node(num, cpu_to_node(num)); - return 0; + return cpuhp_setup_state_nocalls(CPUHP_CPUDEV_PM_PREPARE, + "base/cpu/dev_pm:prepare", + cpu_dev_pm_unset_is_prepared, NULL); } struct device *get_cpu_device(unsigned cpu) diff --git i/include/linux/cpuhotplug.h w/include/linux/cpuhotplug.h index 2ab7bf53d529..5bfe3c1aa148 100644 --- i/include/linux/cpuhotplug.h +++ w/include/linux/cpuhotplug.h @@ -51,6 +51,7 @@ enum cpuhp_state { CPUHP_SLAB_PREPARE, CPUHP_MD_RAID5_PREPARE, CPUHP_RCUTREE_PREP, + CPUHP_CPUDEV_PM_PREPARE, CPUHP_CPUIDLE_COUPLED_PREPARE, CPUHP_POWERPC_PMAC_PREPARE, CPUHP_POWERPC_MMU_CTX_PREPARE, From mboxrd@z Thu Jan 1 00:00:00 1970 From: sudeep.holla@arm.com (Sudeep Holla) Date: Wed, 21 Dec 2016 16:54:22 +0000 Subject: How to remove warn msg "cache: parent cpui should not be sleeping" i=1, 2, 3... In-Reply-To: <20161221193703.6eac880c@xhacker> References: <20161221193703.6eac880c@xhacker> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 21/12/16 11:37, Jisheng Zhang wrote: > Hi all, > > I'm not sure this is a bug, when wake up from s2ram, I could get something > like: > > [ 313.271464] Enabling non-boot CPUs ... > [ 313.271551] CPU1: Booted secondary processor > [ 313.271556] Detected VIPT I-cache on CPU1 > [ 313.301378] cache: parent cpu1 should not be sleeping > [ 313.301504] CPU1 is up > [ 313.301582] CPU2: Booted secondary processor > [ 313.301585] Detected VIPT I-cache on CPU2 > [ 313.331485] cache: parent cpu2 should not be sleeping > [ 313.331605] CPU2 is up > [ 313.331683] CPU3: Booted secondary processor > [ 313.331686] Detected VIPT I-cache on CPU3 > [ 313.361599] cache: parent cpu3 should not be sleeping > [ 313.361719] CPU3 is up > > This is because we call cpu_device_create() when secondary cpu is brought > online, the cpu_cache device's parent device: cpu device isn't already > resumed, all device resume will resume after secondary cores are brought > up. > > What's the elegant solution to remove this warning msg? > It is not a serious warning as you can see a comment in the code: "/* * This is a fib. But we'll allow new children to be added below * a resumed device, even if the device hasn't been completed yet. */" But if we think it needs to be removed, I have something like below in my mind. I am not sure if this is hacky or not(completely untested, not even compiled). Regards, Sudeep -->8 diff --git i/drivers/base/cpu.c w/drivers/base/cpu.c index 4c28e1a09786..2a5c04377adf 100644 --- i/drivers/base/cpu.c +++ w/drivers/base/cpu.c @@ -344,6 +344,14 @@ static int cpu_uevent(struct device *dev, struct kobj_uevent_env *env) } #endif +static int cpu_dev_pm_unset_is_prepared(unsigned int cpu) +{ + struct device *cpu_dev = get_cpu_device(cpu); + + if(cpu_dev) + cpu_dev->power.is_prepared = false; + return 0; +} /* * register_cpu - Setup a sysfs device for a CPU. * @cpu - cpu->hotpluggable field set to 1 will generate a control file in @@ -377,7 +385,9 @@ int register_cpu(struct cpu *cpu, int num) per_cpu(cpu_sys_devices, num) = &cpu->dev; register_cpu_under_node(num, cpu_to_node(num)); - return 0; + return cpuhp_setup_state_nocalls(CPUHP_CPUDEV_PM_PREPARE, + "base/cpu/dev_pm:prepare", + cpu_dev_pm_unset_is_prepared, NULL); } struct device *get_cpu_device(unsigned cpu) diff --git i/include/linux/cpuhotplug.h w/include/linux/cpuhotplug.h index 2ab7bf53d529..5bfe3c1aa148 100644 --- i/include/linux/cpuhotplug.h +++ w/include/linux/cpuhotplug.h @@ -51,6 +51,7 @@ enum cpuhp_state { CPUHP_SLAB_PREPARE, CPUHP_MD_RAID5_PREPARE, CPUHP_RCUTREE_PREP, + CPUHP_CPUDEV_PM_PREPARE, CPUHP_CPUIDLE_COUPLED_PREPARE, CPUHP_POWERPC_PMAC_PREPARE, CPUHP_POWERPC_MMU_CTX_PREPARE,