* [PATCH] Cpufreq: Acquire read lock in the cpufreq_policy_restore() rather than write lock
@ 2013-09-11 7:05 tianyu.lan
2013-09-11 8:09 ` Srivatsa S. Bhat
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: tianyu.lan @ 2013-09-11 7:05 UTC (permalink / raw)
To: rjw, viresh.kumar, srivatsa.bhat
Cc: Lan Tianyu, cpufreq, linux-pm, linux-kernel
From: Lan Tianyu <tianyu.lan@intel.com>
In the cpufreq_policy_restore(), policy before system suspend is read from
from percpu's cpufreq_cpu_data_fallback. It's read operation rather than
write operation. So convert write lock to read lock
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
---
drivers/cpufreq/cpufreq.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 81ceea6..b762f9b 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -912,11 +912,11 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu)
struct cpufreq_policy *policy;
unsigned long flags;
- write_lock_irqsave(&cpufreq_driver_lock, flags);
+ read_lock_irqsave(&cpufreq_driver_lock, flags);
policy = per_cpu(cpufreq_cpu_data_fallback, cpu);
- write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ read_unlock_irqrestore(&cpufreq_driver_lock, flags);
return policy;
}
--
1.8.4.rc0.1.g8f6a3e5.dirty
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] Cpufreq: Acquire read lock in the cpufreq_policy_restore() rather than write lock
2013-09-11 7:05 [PATCH] Cpufreq: Acquire read lock in the cpufreq_policy_restore() rather than write lock tianyu.lan
@ 2013-09-11 8:09 ` Srivatsa S. Bhat
2013-09-11 8:44 ` Viresh Kumar
2013-09-11 22:56 ` Rafael J. Wysocki
2 siblings, 0 replies; 4+ messages in thread
From: Srivatsa S. Bhat @ 2013-09-11 8:09 UTC (permalink / raw)
To: tianyu.lan; +Cc: rjw, viresh.kumar, cpufreq, linux-pm, linux-kernel
On 09/11/2013 12:35 PM, tianyu.lan@intel.com wrote:
> From: Lan Tianyu <tianyu.lan@intel.com>
>
> In the cpufreq_policy_restore(), policy before system suspend is read from
> from percpu's cpufreq_cpu_data_fallback. It's read operation rather than
> write operation. So convert write lock to read lock
>
> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
I noticed it too yesterday, while looking at something else. Thanks for
fixing this!
> ---
> drivers/cpufreq/cpufreq.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 81ceea6..b762f9b 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -912,11 +912,11 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu)
> struct cpufreq_policy *policy;
> unsigned long flags;
>
> - write_lock_irqsave(&cpufreq_driver_lock, flags);
> + read_lock_irqsave(&cpufreq_driver_lock, flags);
>
> policy = per_cpu(cpufreq_cpu_data_fallback, cpu);
>
> - write_unlock_irqrestore(&cpufreq_driver_lock, flags);
> + read_unlock_irqrestore(&cpufreq_driver_lock, flags);
>
> return policy;
> }
>
Regards,
Srivatsa S. Bhat
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Cpufreq: Acquire read lock in the cpufreq_policy_restore() rather than write lock
2013-09-11 7:05 [PATCH] Cpufreq: Acquire read lock in the cpufreq_policy_restore() rather than write lock tianyu.lan
2013-09-11 8:09 ` Srivatsa S. Bhat
@ 2013-09-11 8:44 ` Viresh Kumar
2013-09-11 22:56 ` Rafael J. Wysocki
2 siblings, 0 replies; 4+ messages in thread
From: Viresh Kumar @ 2013-09-11 8:44 UTC (permalink / raw)
To: Lan Tianyu
Cc: Rafael J. Wysocki, Srivatsa S. Bhat, cpufreq@vger.kernel.org,
linux-pm@vger.kernel.org, Linux Kernel Mailing List
On 11 September 2013 12:35, <tianyu.lan@intel.com> wrote:
> From: Lan Tianyu <tianyu.lan@intel.com>
>
> In the cpufreq_policy_restore(), policy before system suspend is read from
> from percpu's cpufreq_cpu_data_fallback. It's read operation rather than
> write operation. So convert write lock to read lock
>
> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
> ---
> drivers/cpufreq/cpufreq.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 81ceea6..b762f9b 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -912,11 +912,11 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu)
> struct cpufreq_policy *policy;
> unsigned long flags;
>
> - write_lock_irqsave(&cpufreq_driver_lock, flags);
> + read_lock_irqsave(&cpufreq_driver_lock, flags);
>
> policy = per_cpu(cpufreq_cpu_data_fallback, cpu);
>
> - write_unlock_irqrestore(&cpufreq_driver_lock, flags);
> + read_unlock_irqrestore(&cpufreq_driver_lock, flags);
>
> return policy;
> }
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Cpufreq: Acquire read lock in the cpufreq_policy_restore() rather than write lock
2013-09-11 7:05 [PATCH] Cpufreq: Acquire read lock in the cpufreq_policy_restore() rather than write lock tianyu.lan
2013-09-11 8:09 ` Srivatsa S. Bhat
2013-09-11 8:44 ` Viresh Kumar
@ 2013-09-11 22:56 ` Rafael J. Wysocki
2 siblings, 0 replies; 4+ messages in thread
From: Rafael J. Wysocki @ 2013-09-11 22:56 UTC (permalink / raw)
To: tianyu.lan; +Cc: viresh.kumar, srivatsa.bhat, cpufreq, linux-pm, linux-kernel
On Wednesday, September 11, 2013 03:05:05 PM tianyu.lan@intel.com wrote:
> From: Lan Tianyu <tianyu.lan@intel.com>
>
> In the cpufreq_policy_restore(), policy before system suspend is read from
> from percpu's cpufreq_cpu_data_fallback. It's read operation rather than
> write operation. So convert write lock to read lock
>
> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Applied, thanks Tianyu!
> ---
> drivers/cpufreq/cpufreq.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 81ceea6..b762f9b 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -912,11 +912,11 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu)
> struct cpufreq_policy *policy;
> unsigned long flags;
>
> - write_lock_irqsave(&cpufreq_driver_lock, flags);
> + read_lock_irqsave(&cpufreq_driver_lock, flags);
>
> policy = per_cpu(cpufreq_cpu_data_fallback, cpu);
>
> - write_unlock_irqrestore(&cpufreq_driver_lock, flags);
> + read_unlock_irqrestore(&cpufreq_driver_lock, flags);
>
> return policy;
> }
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-09-11 22:56 UTC | newest]
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2013-09-11 7:05 [PATCH] Cpufreq: Acquire read lock in the cpufreq_policy_restore() rather than write lock tianyu.lan
2013-09-11 8:09 ` Srivatsa S. Bhat
2013-09-11 8:44 ` Viresh Kumar
2013-09-11 22:56 ` Rafael J. Wysocki
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