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authorAndi Kleen <ak@suse.de>2007-10-10 02:18:27 +0200
committerDave Jones <davej@redhat.com>2007-10-10 03:44:06 +0200
commit9eb59573d4b86f347e6cd04f47a4c2082009fa58 (patch)
tree91209b4149bf791c36ed50da3d0261f491cd27b4
parent[CPUFREQ] Support different families in fid/did to frequency conversion (diff)
downloadlinux-9eb59573d4b86f347e6cd04f47a4c2082009fa58.tar.xz
linux-9eb59573d4b86f347e6cd04f47a4c2082009fa58.zip
[CPUFREQ] Don't take semaphore in cpufreq_quick_get()
I don't see any reason to take an expensive lock in cpufreq_quick_get() Reading policy->cur is a single atomic operation and after the lock is dropped again the state could change any time anyways. So don't take the lock in the first place. This also makes this function interrupt safe which is useful for some code of mine. Signed-off-by: Andi Kleen <ak@suse.de> Cc: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
-rw-r--r--drivers/cpufreq/cpufreq.c5
1 files changed, 0 insertions, 5 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index e027052a6604..f7b9d6fce123 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1111,12 +1111,7 @@ unsigned int cpufreq_quick_get(unsigned int cpu)
unsigned int ret_freq = 0;
if (policy) {
- if (unlikely(lock_policy_rwsem_read(cpu)))
- return ret_freq;
-
ret_freq = policy->cur;
-
- unlock_policy_rwsem_read(cpu);
cpufreq_cpu_put(policy);
}