lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[CPUFREQ] Rewrite lock in cpufreq to eliminate cpufreq/hotplug related issues

Browse Source 
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 <ego@in.ibm.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Jones <davej@redhat.com>
This commit is contained in:
Venkatesh Pallipadi
2007-02-05 16:12:44 -08:00
committed by Dave Jones
parent c120069779
commit 5a01f2e8f3
2 changed files with 187 additions and 67 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
include/linux/cpufreq.h
View File

@ -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 *