2013-03-05 22:15:40

by Dirk Brandewie

[permalink] [raw]
Subject: [PATCH 0/2] v3.9-rc1 fixes for intel_pstate driver

From: Dirk Brandewie <[email protected]>

These patches fix the issues reported against the intel_pstate driver.

The first bug reported by Josh Boyer was that the dirver would blow up
when loading in a VM exposed the second bug that the error path in
intel_pstate_init() was incorrect and biting Konrad Wilk as well.

https://bugzilla.redhat.com/show_bug.cgi?id=916833
https://lkml.org/lkml/2013/3/5/394

Dirk Brandewie (2):
cpufreq/intel_pstate: Do not load on VM that do not report max P
state.
cpufreq/intel_pstate: Fix intel_pstate_init() error path

drivers/cpufreq/intel_pstate.c | 42 +++++++++++++--------------------------
1 files changed, 14 insertions(+), 28 deletions(-)

--
1.7.7.6


2013-03-05 22:15:47

by Dirk Brandewie

[permalink] [raw]
Subject: [PATCH 1/2] cpufreq/intel_pstate: Do not load on VM that do not report max P state.

From: Dirk Brandewie <[email protected]>

It seems some VMs support the P state MSRs but return zeros. Fail
gracefully if we are running in this environment.

https://bugzilla.redhat.com/show_bug.cgi?id=916833

Reported-by: [email protected]
Signed-off-by: Dirk Brandewie <[email protected]>
---
drivers/cpufreq/intel_pstate.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 096fde0..2bfd083 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -662,6 +662,9 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)

cpu = all_cpu_data[policy->cpu];

+ if (!policy->cpuinfo.max_freq)
+ return -ENODEV;
+
intel_pstate_get_min_max(cpu, &min, &max);

limits.min_perf_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
--
1.7.7.6

2013-03-05 22:15:45

by Dirk Brandewie

[permalink] [raw]
Subject: [PATCH 2/2] cpufreq/intel_pstate: Fix intel_pstate_init() error path

From: Dirk Brandewie <[email protected]>

If cpufreq_register_driver() fails just free memory that has been
allocated and return. intel_pstate_exit() function is removed sine we
are built-in only now there is no reason for a module exit proceedure.

Reported-by:Konrad Rzeszutek Wilk <[email protected]>
Signed-off-by: Dirk Brandewie <[email protected]>
---
drivers/cpufreq/intel_pstate.c | 39 +++++++++++----------------------------
1 files changed, 11 insertions(+), 28 deletions(-)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 2bfd083..f6dd1e7 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -750,37 +750,11 @@ static struct cpufreq_driver intel_pstate_driver = {
.owner = THIS_MODULE,
};

-static void intel_pstate_exit(void)
-{
- int cpu;
-
- sysfs_remove_group(intel_pstate_kobject,
- &intel_pstate_attr_group);
- debugfs_remove_recursive(debugfs_parent);
-
- cpufreq_unregister_driver(&intel_pstate_driver);
-
- if (!all_cpu_data)
- return;
-
- get_online_cpus();
- for_each_online_cpu(cpu) {
- if (all_cpu_data[cpu]) {
- del_timer_sync(&all_cpu_data[cpu]->timer);
- kfree(all_cpu_data[cpu]);
- }
- }
-
- put_online_cpus();
- vfree(all_cpu_data);
-}
-module_exit(intel_pstate_exit);
-
static int __initdata no_load;

static int __init intel_pstate_init(void)
{
- int rc = 0;
+ int cpu, rc = 0;
const struct x86_cpu_id *id;

if (no_load)
@@ -805,7 +779,16 @@ static int __init intel_pstate_init(void)
intel_pstate_sysfs_expose_params();
return rc;
out:
- intel_pstate_exit();
+ get_online_cpus();
+ for_each_online_cpu(cpu) {
+ if (all_cpu_data[cpu]) {
+ del_timer_sync(&all_cpu_data[cpu]->timer);
+ kfree(all_cpu_data[cpu]);
+ }
+ }
+
+ put_online_cpus();
+ vfree(all_cpu_data);
return -ENODEV;
}
device_initcall(intel_pstate_init);
--
1.7.7.6

2013-03-06 13:37:28

by Viresh Kumar

[permalink] [raw]
Subject: Re: [PATCH 2/2] cpufreq/intel_pstate: Fix intel_pstate_init() error path

On Wed, Mar 6, 2013 at 6:15 AM, <[email protected]> wrote:
> From: Dirk Brandewie <[email protected]>
>
> If cpufreq_register_driver() fails just free memory that has been
> allocated and return. intel_pstate_exit() function is removed sine we

s/sine/since

> are built-in only now there is no reason for a module exit proceedure.

s/proceedure/procedure

> Reported-by:Konrad Rzeszutek Wilk <[email protected]>
> Signed-off-by: Dirk Brandewie <[email protected]>
> ---
> drivers/cpufreq/intel_pstate.c | 39 +++++++++++----------------------------
> 1 files changed, 11 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index 2bfd083..f6dd1e7 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -750,37 +750,11 @@ static struct cpufreq_driver intel_pstate_driver = {
> .owner = THIS_MODULE,
> };
>
> -static void intel_pstate_exit(void)
> -{
> - int cpu;
> -
> - sysfs_remove_group(intel_pstate_kobject,
> - &intel_pstate_attr_group);
> - debugfs_remove_recursive(debugfs_parent);
> -
> - cpufreq_unregister_driver(&intel_pstate_driver);
> -
> - if (!all_cpu_data)
> - return;
> -
> - get_online_cpus();
> - for_each_online_cpu(cpu) {
> - if (all_cpu_data[cpu]) {
> - del_timer_sync(&all_cpu_data[cpu]->timer);
> - kfree(all_cpu_data[cpu]);
> - }
> - }
> -
> - put_online_cpus();
> - vfree(all_cpu_data);
> -}
> -module_exit(intel_pstate_exit);
> -
> static int __initdata no_load;
>
> static int __init intel_pstate_init(void)
> {
> - int rc = 0;
> + int cpu, rc = 0;
> const struct x86_cpu_id *id;
>
> if (no_load)
> @@ -805,7 +779,16 @@ static int __init intel_pstate_init(void)
> intel_pstate_sysfs_expose_params();
> return rc;
> out:
> - intel_pstate_exit();
> + get_online_cpus();
> + for_each_online_cpu(cpu) {
> + if (all_cpu_data[cpu]) {
> + del_timer_sync(&all_cpu_data[cpu]->timer);
> + kfree(all_cpu_data[cpu]);
> + }
> + }
> +
> + put_online_cpus();
> + vfree(all_cpu_data);
> return -ENODEV;
> }
> device_initcall(intel_pstate_init);
> --
> 1.7.7.6
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/

2013-03-06 13:37:52

by Viresh Kumar

[permalink] [raw]
Subject: Re: [PATCH 0/2] v3.9-rc1 fixes for intel_pstate driver

On Wed, Mar 6, 2013 at 6:15 AM, <[email protected]> wrote:
> From: Dirk Brandewie <[email protected]>
>
> These patches fix the issues reported against the intel_pstate driver.
>
> The first bug reported by Josh Boyer was that the dirver would blow up

s/dirver/driver :)

> when loading in a VM exposed the second bug that the error path in
> intel_pstate_init() was incorrect and biting Konrad Wilk as well.
>
> https://bugzilla.redhat.com/show_bug.cgi?id=916833
> https://lkml.org/lkml/2013/3/5/394

Acked-by: Viresh Kumar <[email protected]>