From 5a01f2e8f3ac134e24144d74bb48a60236f7024d Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Mon, 5 Feb 2007 16:12:44 -0800 Subject: [CPUFREQ] Rewrite lock in cpufreq to eliminate cpufreq/hotplug related issues Yet another attempt to resolve cpufreq and hotplug locking issues. Patchset has 3 patches: * Rewrite the lock infrastructure of cpufreq using a per cpu rwsem. * Minor restructuring of work callback in ondemand driver. * Use the new cpufreq rwsem infrastructure in ondemand work. This patch: Convert policy->lock to rwsem and move it to per_cpu area. This rwsem will protect against both changing/accessing policy related parameters and CPU hot plug/unplug. [malattia@linux.it: fix oops in kref_put()] Cc: Gautham R Shenoy Signed-off-by: Venkatesh Pallipadi Cc: Gautham R Shenoy Signed-off-by: Mattia Dongili Signed-off-by: Andrew Morton Signed-off-by: Dave Jones --- include/linux/cpufreq.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 7f008f6bfdc3..0899e2cdcdd1 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -84,9 +84,6 @@ struct cpufreq_policy { unsigned int policy; /* see above */ struct cpufreq_governor *governor; /* see below */ - struct mutex lock; /* CPU ->setpolicy or ->target may - only be called once a time */ - struct work_struct update; /* if update_policy() needs to be * called, but you're in IRQ context */ @@ -172,11 +169,16 @@ extern int __cpufreq_driver_target(struct cpufreq_policy *policy, unsigned int relation); -extern int cpufreq_driver_getavg(struct cpufreq_policy *policy); +extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy); int cpufreq_register_governor(struct cpufreq_governor *governor); void cpufreq_unregister_governor(struct cpufreq_governor *governor); +int lock_policy_rwsem_read(int cpu); +int lock_policy_rwsem_write(int cpu); +void unlock_policy_rwsem_read(int cpu); +void unlock_policy_rwsem_write(int cpu); + /********************************************************************* * CPUFREQ DRIVER INTERFACE * -- cgit v1.2.3