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
--
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