Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1411078 > unrolled thread

[PATCH 3/8] cpufreq: powerenv: Fix memory leak

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  [PATCH 3/8] cpufreq: powerenv: Fix memory leak Viresh Kumar <viresh.kumar@linaro.org> - 2016-06-01 12:40 +0200
    Re: [PATCH 3/8] cpufreq: powerenv: Fix memory leak Michael Ellerman <mpe@ellerman.id.au> - 2016-06-02 13:10 +0200
      Re: [PATCH 3/8] cpufreq: powerenv: Fix memory leak Viresh Kumar <viresh.kumar@linaro.org> - 2016-06-02 13:30 +0200
        Re: [PATCH 3/8] cpufreq: powerenv: Fix memory leak Michael Ellerman <mpe@ellerman.id.au> - 2016-06-02 13:40 +0200
          Re: [PATCH 3/8] cpufreq: powerenv: Fix memory leak Viresh Kumar <viresh.kumar@linaro.org> - 2016-06-02 13:50 +0200
            Re: [PATCH 3/8] cpufreq: powerenv: Fix memory leak Michael Ellerman <mpe@ellerman.id.au> - 2016-06-02 14:10 +0200

#1411078 — [PATCH 3/8] cpufreq: powerenv: Fix memory leak

The policy is copied (unnecessarily) and is never freed. Fix it by just
getting a reference to the existing policy structure and putting it
back.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/cpufreq/powernv-cpufreq.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index 54c45368e3f1..96bb4acd366e 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -756,15 +756,18 @@ void powernv_cpufreq_work_fn(struct work_struct *work)
 
 	chip->restore = false;
 	for_each_cpu(cpu, &mask) {
+		struct cpufreq_policy *policy = cpufreq_cpu_get(cpu)
 		int index;
-		struct cpufreq_policy policy;
 
-		cpufreq_get_policy(&policy, cpu);
-		cpufreq_frequency_table_target(&policy, policy.freq_table,
-					       policy.cur,
+		if (!policy)
+			continue;
+
+		cpufreq_frequency_table_target(policy, policy->freq_table,
+					       policy->cur,
 					       CPUFREQ_RELATION_C, &index);
-		powernv_cpufreq_target_index(&policy, index);
-		cpumask_andnot(&mask, &mask, policy.cpus);
+		powernv_cpufreq_target_index(policy, index);
+		cpumask_andnot(&mask, &mask, policy->cpus);
+		cpufreq_cpu_put(policy);
 	}
 out:
 	put_online_cpus();
-- 
2.7.1.410.g6faf27b

[toc] | [next] | [standalone]

#1412134

On Wed, 2016-06-01 at 16:04 +0530, Viresh Kumar wrote:

> The policy is copied (unnecessarily) and is never freed. Fix it by just
> getting a reference to the existing policy structure and putting it
> back.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

When was it broken, always?

Cc: stable ?

cheers

[toc] | [prev] | [next] | [standalone]

#1412140

On 02-06-16, 21:08, Michael Ellerman wrote:
> On Wed, 2016-06-01 at 16:04 +0530, Viresh Kumar wrote:
> 
> > The policy is copied (unnecessarily) and is never freed. Fix it by just
> > getting a reference to the existing policy structure and putting it
> > back.
> > 
> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> 
> When was it broken, always?
> 
> Cc: stable ?

Its a small memory leak and its not that we will fail on something. So
didn't bother to add those details, but in case they are required:

Cc: <stable@vger.kernel.org> # 4.3+
Fixes: 227942809b52 ("cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling")

-- 
viresh

[toc] | [prev] | [next] | [standalone]

#1412141

On Thu, 2016-06-02 at 16:52 +0530, Viresh Kumar wrote:
> On 02-06-16, 21:08, Michael Ellerman wrote:
> > On Wed, 2016-06-01 at 16:04 +0530, Viresh Kumar wrote:
> > 
> > > The policy is copied (unnecessarily) and is never freed. Fix it by just
> > > getting a reference to the existing policy structure and putting it
> > > back.
> > > 
> > > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> > 
> > When was it broken, always?
> > 
> > Cc: stable ?
> 
> Its a small memory leak and its not that we will fail on something. So
> didn't bother to add those details, but in case they are required:
> 
> Cc: <stable@vger.kernel.org> # 4.3+
> Fixes: 227942809b52 ("cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling")

OK. I can't actually see where the copy is?

But if we are leaking even a small amount of memory in a loop like that, in a
function that's run semi-regularly, then it's going to add up eventually.

cheers

[toc] | [prev] | [next] | [standalone]

#1412149

On 02-06-16, 21:37, Michael Ellerman wrote:
> On Thu, 2016-06-02 at 16:52 +0530, Viresh Kumar wrote:
> > On 02-06-16, 21:08, Michael Ellerman wrote:
> > > On Wed, 2016-06-01 at 16:04 +0530, Viresh Kumar wrote:
> > > 
> > > > The policy is copied (unnecessarily) and is never freed. Fix it by just
> > > > getting a reference to the existing policy structure and putting it
> > > > back.
> > > > 
> > > > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> > > 
> > > When was it broken, always?
> > > 
> > > Cc: stable ?
> > 
> > Its a small memory leak and its not that we will fail on something. So
> > didn't bother to add those details, but in case they are required:
> > 
> > Cc: <stable@vger.kernel.org> # 4.3+
> > Fixes: 227942809b52 ("cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling")
> 
> OK. I can't actually see where the copy is?
> 
> But if we are leaking even a small amount of memory in a loop like that, in a
> function that's run semi-regularly, then it's going to add up eventually.

Urg, it wasn't a memory leak actually. I misread.

I somehow thought that cpufreq_get_policy() is also allocating memory
for the policy, but it just memcpy's it into the callers buffer. So,
that's not a problem really.

This patch should be just dropped. Sorry for the noise.

-- 
viresh

[toc] | [prev] | [next] | [standalone]

#1412167

On Thu, 2016-06-02 at 17:13 +0530, Viresh Kumar wrote:
> On 02-06-16, 21:37, Michael Ellerman wrote:
> > On Thu, 2016-06-02 at 16:52 +0530, Viresh Kumar wrote:
> > > On 02-06-16, 21:08, Michael Ellerman wrote:
> > > > On Wed, 2016-06-01 at 16:04 +0530, Viresh Kumar wrote:
> > > > 
> > > > > The policy is copied (unnecessarily) and is never freed. Fix it by just
> > > > > getting a reference to the existing policy structure and putting it
> > > > > back.
> > > > > 
> > > > > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> > > > 
> > > > When was it broken, always?
> > > > 
> > > > Cc: stable ?
> > > 
> > > Its a small memory leak and its not that we will fail on something. So
> > > didn't bother to add those details, but in case they are required:
> > > 
> > > Cc: <stable@vger.kernel.org> # 4.3+
> > > Fixes: 227942809b52 ("cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling")
> > 
> > OK. I can't actually see where the copy is?
> > 
> > But if we are leaking even a small amount of memory in a loop like that, in a
> > function that's run semi-regularly, then it's going to add up eventually.
> 
> Urg, it wasn't a memory leak actually. I misread.
> 
> I somehow thought that cpufreq_get_policy() is also allocating memory
> for the policy, but it just memcpy's it into the callers buffer. So,
> that's not a problem really.
> 
> This patch should be just dropped. Sorry for the noise.

OK, no worries.

cheers

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web