From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 8C60DB6F89 for ; Fri, 17 Jun 2011 14:29:19 +1000 (EST) Subject: Re: [RFC PATCH V1 1/7] cpuidle: create bootparam "cpuidle.off=1" From: Benjamin Herrenschmidt To: Trinabh Gupta In-Reply-To: <20110607162922.6848.71783.stgit@tringupt.in.ibm.com> References: <20110607162847.6848.44707.stgit@tringupt.in.ibm.com> <20110607162922.6848.71783.stgit@tringupt.in.ibm.com> Content-Type: text/plain; charset="UTF-8" Date: Fri, 17 Jun 2011 14:29:08 +1000 Message-ID: <1308284948.32158.6.camel@pasglop> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 2011-06-07 at 21:59 +0530, Trinabh Gupta wrote: > From: Len Brown > > useful for disabling cpuidle to fall back > to architecture-default idle loop > > cpuidle drivers and governors will fail to register. > on x86 they'll say so: > > intel_idle: intel_idle yielding to (null) > ACPI: acpi_idle yielding to (null) > > Signed-off-by: Len Brown > --- When you carry over somebody's patch like this you need to also add your own signed-off-by. Have those generic changes been reviewed by whoever is in charge of that cpuidle framework ? Cheers, Ben. > Documentation/kernel-parameters.txt | 3 +++ > drivers/cpuidle/cpuidle.c | 10 ++++++++++ > drivers/cpuidle/cpuidle.h | 1 + > drivers/cpuidle/driver.c | 3 +++ > drivers/cpuidle/governor.c | 3 +++ > 5 files changed, 20 insertions(+), 0 deletions(-) > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > index d9a203b..5697faf 100644 > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -546,6 +546,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > /proc//coredump_filter. > See also Documentation/filesystems/proc.txt. > > + cpuidle.off=1 [CPU_IDLE] > + disable the cpuidle sub-system > + > cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver > Format: > ,,,[,] > diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c > index 406be83..a171b9e 100644 > --- a/drivers/cpuidle/cpuidle.c > +++ b/drivers/cpuidle/cpuidle.c > @@ -28,6 +28,12 @@ LIST_HEAD(cpuidle_detected_devices); > static void (*pm_idle_old)(void); > > static int enabled_devices; > +static int off __read_mostly; > + > +int cpuidle_disabled(void) > +{ > + return off; > +} > > #if defined(CONFIG_ARCH_HAS_CPU_IDLE_WAIT) > static void cpuidle_kick_cpus(void) > @@ -397,6 +403,9 @@ static int __init cpuidle_init(void) > { > int ret; > > + if (cpuidle_disabled()) > + return -ENODEV; > + > pm_idle_old = pm_idle; > > ret = cpuidle_add_class_sysfs(&cpu_sysdev_class); > @@ -408,4 +417,5 @@ static int __init cpuidle_init(void) > return 0; > } > > +module_param(off, int, 0444); > core_initcall(cpuidle_init); > diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h > index 33e50d5..38c3fd8 100644 > --- a/drivers/cpuidle/cpuidle.h > +++ b/drivers/cpuidle/cpuidle.h > @@ -13,6 +13,7 @@ extern struct list_head cpuidle_governors; > extern struct list_head cpuidle_detected_devices; > extern struct mutex cpuidle_lock; > extern spinlock_t cpuidle_driver_lock; > +extern int cpuidle_disabled(void); > > /* idle loop */ > extern void cpuidle_install_idle_handler(void); > diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c > index 33e3189..284d7af 100644 > --- a/drivers/cpuidle/driver.c > +++ b/drivers/cpuidle/driver.c > @@ -50,6 +50,9 @@ int cpuidle_register_driver(struct cpuidle_driver *drv) > if (!drv) > return -EINVAL; > > + if (cpuidle_disabled()) > + return -ENODEV; > + > spin_lock(&cpuidle_driver_lock); > if (cpuidle_curr_driver) { > spin_unlock(&cpuidle_driver_lock); > diff --git a/drivers/cpuidle/governor.c b/drivers/cpuidle/governor.c > index 724c164..ea2f8e7 100644 > --- a/drivers/cpuidle/governor.c > +++ b/drivers/cpuidle/governor.c > @@ -81,6 +81,9 @@ int cpuidle_register_governor(struct cpuidle_governor *gov) > if (!gov || !gov->select) > return -EINVAL; > > + if (cpuidle_disabled()) > + return -ENODEV; > + > mutex_lock(&cpuidle_lock); > if (__cpuidle_find_governor(gov->name) == NULL) { > ret = 0; > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev