Dear RT folks! I'm pleased to announce the v4.1.3-rt3 patch set. Changes since v4.1.3-rt2: - fix compile of locktorture. Patch by Wolfgang M. Reimer. - fix compile pid_namespace without lockdep on ARM. Patch by Grygorii Strashko - The annoying "cpufreq_stat_notifier_trans: No policy found" is finally gone. - xor / raid_pq The max latency will increase into the ms range if the raid6_pq is loaded. This should not matter under normal circumstances because that module should only be loaded at boot time if required (and not while a -RT task is active in production). It might also get loaded at run-time manually. Dropping the preempt_disable() might cause different results for the individual implementations. People who don't care (load it at run-time) don't need to load it at all. People who care (load it boot time) would prefer to stick with the best implementation. Therefore I think it is enough to document this (don't load it at run time if you don't need it) and I cross it off my list. Patches are welcome if someone needs / has an improvement. Known issues: - bcache is disabled. - CPU hotplug works in general. Steven's test script however deadlocks usually on the second invocation. You can get this release via the git tree at: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt-rebase git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt-queue The delta patch against 4.0.8-rt5 is appended below and can be found here: https://www.kernel.org/pub/linux/kernel/projects/rt/4.1/incr/patch-4.1.3-rt2-rt3.patch.xz The RT patch against 4.1.3 can be found here: https://www.kernel.org/pub/linux/kernel/projects/rt/4.1/patch-4.1.3-rt3.patch.xz The split quilt queue is available at: https://www.kernel.org/pub/linux/kernel/projects/rt/4.1/patches-4.1.3-rt3.tar.xz Sebastian diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 8ae655c364f4..ce1d93e93d1a 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -64,12 +64,6 @@ static inline bool has_target(void) return cpufreq_driver->target_index || cpufreq_driver->target; } -/* - * rwsem to guarantee that cpufreq driver module doesn't unload during critical - * sections - */ -static DECLARE_RWSEM(cpufreq_rwsem); - /* internal prototypes */ static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event); @@ -215,9 +209,6 @@ struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) if (cpu >= nr_cpu_ids) return NULL; - if (!down_read_trylock(&cpufreq_rwsem)) - return NULL; - /* get the cpufreq driver */ read_lock_irqsave(&cpufreq_driver_lock, flags); @@ -230,9 +221,6 @@ struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) read_unlock_irqrestore(&cpufreq_driver_lock, flags); - if (!policy) - up_read(&cpufreq_rwsem); - return policy; } EXPORT_SYMBOL_GPL(cpufreq_cpu_get); @@ -240,7 +228,6 @@ EXPORT_SYMBOL_GPL(cpufreq_cpu_get); void cpufreq_cpu_put(struct cpufreq_policy *policy) { kobject_put(&policy->kobj); - up_read(&cpufreq_rwsem); } EXPORT_SYMBOL_GPL(cpufreq_cpu_put); @@ -765,9 +752,6 @@ static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) struct freq_attr *fattr = to_attr(attr); ssize_t ret; - if (!down_read_trylock(&cpufreq_rwsem)) - return -EINVAL; - down_read(&policy->rwsem); if (fattr->show) @@ -776,7 +760,6 @@ static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) ret = -EIO; up_read(&policy->rwsem); - up_read(&cpufreq_rwsem); return ret; } @@ -793,9 +776,6 @@ static ssize_t store(struct kobject *kobj, struct attribute *attr, if (!cpu_online(policy->cpu)) goto unlock; - if (!down_read_trylock(&cpufreq_rwsem)) - goto unlock; - down_write(&policy->rwsem); if (fattr->store) @@ -804,8 +784,6 @@ static ssize_t store(struct kobject *kobj, struct attribute *attr, ret = -EIO; up_write(&policy->rwsem); - - up_read(&cpufreq_rwsem); unlock: put_online_cpus(); @@ -1117,16 +1095,12 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) if (unlikely(policy)) return 0; - if (!down_read_trylock(&cpufreq_rwsem)) - return 0; - /* Check if this cpu was hot-unplugged earlier and has siblings */ read_lock_irqsave(&cpufreq_driver_lock, flags); for_each_policy(policy) { if (cpumask_test_cpu(cpu, policy->related_cpus)) { read_unlock_irqrestore(&cpufreq_driver_lock, flags); ret = cpufreq_add_policy_cpu(policy, cpu, dev); - up_read(&cpufreq_rwsem); return ret; } } @@ -1269,8 +1243,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) kobject_uevent(&policy->kobj, KOBJ_ADD); - up_read(&cpufreq_rwsem); - /* Callback for handling stuff after policy is ready */ if (cpufreq_driver->ready) cpufreq_driver->ready(policy); @@ -1304,8 +1276,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) cpufreq_policy_free(policy); nomem_out: - up_read(&cpufreq_rwsem); - return ret; } @@ -2499,19 +2469,20 @@ int cpufreq_unregister_driver(struct cpufreq_driver *driver) pr_debug("unregistering driver %s\n", driver->name); + /* Protect against concurrent cpu hotplug */ + get_online_cpus(); subsys_interface_unregister(&cpufreq_interface); if (cpufreq_boost_supported()) cpufreq_sysfs_remove_file(&boost.attr); unregister_hotcpu_notifier(&cpufreq_cpu_notifier); - down_write(&cpufreq_rwsem); write_lock_irqsave(&cpufreq_driver_lock, flags); cpufreq_driver = NULL; write_unlock_irqrestore(&cpufreq_driver_lock, flags); - up_write(&cpufreq_rwsem); + put_online_cpus(); return 0; } diff --git a/include/linux/pid.h b/include/linux/pid.h index 23705a53abba..2cc64b779f03 100644 --- a/include/linux/pid.h +++ b/include/linux/pid.h @@ -2,6 +2,7 @@ #define _LINUX_PID_H #include <linux/rcupdate.h> +#include <linux/atomic.h> enum pid_type { diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index ec8cce259779..aa60d919e336 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -24,7 +24,6 @@ #include <linux/module.h> #include <linux/kthread.h> #include <linux/spinlock.h> -#include <linux/rwlock.h> #include <linux/mutex.h> #include <linux/rwsem.h> #include <linux/smp.h> diff --git a/localversion-rt b/localversion-rt index c3054d08a112..1445cd65885c 100644 --- a/localversion-rt +++ b/localversion-rt @@ -1 +1 @@ --rt2 +-rt3 -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html