diff mbox

[RFC,1/3] PM / Domains: Allocate memory outside domain locks

Message ID 1433456946-53296-2-git-send-email-lina.iyer@linaro.org (mailing list archive)
State RFC, archived
Headers show

Commit Message

Lina Iyer June 4, 2015, 10:29 p.m. UTC
In order for domains to be powered on/off in irq locked context, the
domain locks could either be a spinlock or a mutex, depending on the
domain. In preparation for atomic support, allocate domain data outside
the domain locks, so the allocation calls dont have to be context
sensitive.

Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
---
 drivers/base/power/domain.c | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

Comments

Krzysztof Kozlowski June 7, 2015, 8:35 a.m. UTC | #1
W dniu 05.06.2015 o 07:29, Lina Iyer pisze:
> In order for domains to be powered on/off in irq locked context, the
> domain locks could either be a spinlock or a mutex, depending on the
> domain. In preparation for atomic support, allocate domain data outside
> the domain locks, so the allocation calls dont have to be context
> sensitive.
> 
> Cc: Ulf Hansson <ulf.hansson@linaro.org>
> Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
> Cc: Kevin Hilman <khilman@linaro.org>
> Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
> ---
>  drivers/base/power/domain.c | 25 ++++++++++++-------------
>  1 file changed, 12 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index 3b3367b..dfd7595 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -1367,13 +1367,17 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
>  int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
>  			   struct generic_pm_domain *subdomain)
>  {
> -	struct gpd_link *link;
> +	struct gpd_link *link, *itr;
>  	int ret = 0;
>  
>  	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)
>  	    || genpd == subdomain)
>  		return -EINVAL;
>  
> +	link = kzalloc(sizeof(*link), GFP_KERNEL);
> +	if (!link)
> +		return -ENOMEM;
> +
>  	mutex_lock(&genpd->lock);
>  	mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
>  
> @@ -1383,18 +1387,13 @@ int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
>  		goto out;
>  	}
>  
> -	list_for_each_entry(link, &genpd->master_links, master_node) {
> -		if (link->slave == subdomain && link->master == genpd) {
> +	list_for_each_entry(itr, &genpd->master_links, master_node) {
> +		if (itr->slave == subdomain && itr->master == genpd) {
>  			ret = -EINVAL;
>  			goto out;
>  		}
>  	}
>  
> -	link = kzalloc(sizeof(*link), GFP_KERNEL);
> -	if (!link) {
> -		ret = -ENOMEM;
> -		goto out;
> -	}
>  	link->master = genpd;
>  	list_add_tail(&link->master_node, &genpd->master_links);
>  	link->slave = subdomain;
> @@ -1496,17 +1495,17 @@ int pm_genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state)
>  	if (IS_ERR_OR_NULL(genpd) || state < 0)
>  		return -EINVAL;
>  
> +	cpuidle_data = kzalloc(sizeof(*cpuidle_data), GFP_KERNEL);
> +	if (!cpuidle_data)
> +		return -ENOMEM;
> +
>  	mutex_lock(&genpd->lock);
>  
>  	if (genpd->cpuidle_data) {
>  		ret = -EEXIST;
>  		goto out;

I think you must update the error paths. In this case the kfree() is
missing.

Best regards,
Krzysztof

>  	}
> -	cpuidle_data = kzalloc(sizeof(*cpuidle_data), GFP_KERNEL);
> -	if (!cpuidle_data) {
> -		ret = -ENOMEM;
> -		goto out;
> -	}
> +
>  	cpuidle_drv = cpuidle_driver_ref();
>  	if (!cpuidle_drv) {
>  		ret = -ENODEV;
> 

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Lina Iyer June 9, 2015, 10:45 p.m. UTC | #2
On Sun, Jun 07 2015 at 02:35 -0600, Krzysztof Kozlowski wrote:
>W dniu 05.06.2015 o 07:29, Lina Iyer pisze:
>> In order for domains to be powered on/off in irq locked context, the
>> domain locks could either be a spinlock or a mutex, depending on the
>> domain. In preparation for atomic support, allocate domain data outside
>> the domain locks, so the allocation calls dont have to be context
>> sensitive.
>>
>> Cc: Ulf Hansson <ulf.hansson@linaro.org>
>> Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
>> Cc: Kevin Hilman <khilman@linaro.org>
>> Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
>> ---
>>  drivers/base/power/domain.c | 25 ++++++++++++-------------
>>  1 file changed, 12 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
>> index 3b3367b..dfd7595 100644
>> --- a/drivers/base/power/domain.c
>> +++ b/drivers/base/power/domain.c
>> @@ -1367,13 +1367,17 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
>>  int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
>>  			   struct generic_pm_domain *subdomain)
>>  {
>> -	struct gpd_link *link;
>> +	struct gpd_link *link, *itr;
>>  	int ret = 0;
>>
>>  	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)
>>  	    || genpd == subdomain)
>>  		return -EINVAL;
>>
>> +	link = kzalloc(sizeof(*link), GFP_KERNEL);
>> +	if (!link)
>> +		return -ENOMEM;
>> +
>>  	mutex_lock(&genpd->lock);
>>  	mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
>>
>> @@ -1383,18 +1387,13 @@ int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
>>  		goto out;
>>  	}
>>
>> -	list_for_each_entry(link, &genpd->master_links, master_node) {
>> -		if (link->slave == subdomain && link->master == genpd) {
>> +	list_for_each_entry(itr, &genpd->master_links, master_node) {
>> +		if (itr->slave == subdomain && itr->master == genpd) {
>>  			ret = -EINVAL;
>>  			goto out;
>>  		}
>>  	}
>>
>> -	link = kzalloc(sizeof(*link), GFP_KERNEL);
>> -	if (!link) {
>> -		ret = -ENOMEM;
>> -		goto out;
>> -	}
>>  	link->master = genpd;
>>  	list_add_tail(&link->master_node, &genpd->master_links);
>>  	link->slave = subdomain;
>> @@ -1496,17 +1495,17 @@ int pm_genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state)
>>  	if (IS_ERR_OR_NULL(genpd) || state < 0)
>>  		return -EINVAL;
>>
>> +	cpuidle_data = kzalloc(sizeof(*cpuidle_data), GFP_KERNEL);
>> +	if (!cpuidle_data)
>> +		return -ENOMEM;
>> +
>>  	mutex_lock(&genpd->lock);
>>
>>  	if (genpd->cpuidle_data) {
>>  		ret = -EEXIST;
>>  		goto out;
>
>I think you must update the error paths. In this case the kfree() is
>missing.
>
Yes, thank you. Will fix.

-- Lina
>
>>  	}
>> -	cpuidle_data = kzalloc(sizeof(*cpuidle_data), GFP_KERNEL);
>> -	if (!cpuidle_data) {
>> -		ret = -ENOMEM;
>> -		goto out;
>> -	}
>> +
>>  	cpuidle_drv = cpuidle_driver_ref();
>>  	if (!cpuidle_drv) {
>>  		ret = -ENODEV;
>>
>
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Kevin Hilman June 10, 2015, 5:33 p.m. UTC | #3
Lina Iyer <lina.iyer@linaro.org> writes:

> In order for domains to be powered on/off in irq locked context, the
> domain locks could either be a spinlock or a mutex, depending on the
> domain. 

I'd drop that sentence.

> In preparation for atomic support, allocate domain data outside

In preparation for supporting IRQ-safe domainss, ...

> the domain locks, so the allocation calls dont have to be context
> sensitive.

OK, but *why* don't these allocations need to be protected by the
locks.  Presumably they were put inside the locks for a reason, so you
should make the case for why the lock protection isn't needed.

Kevin

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diff mbox

Patch

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 3b3367b..dfd7595 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1367,13 +1367,17 @@  int pm_genpd_remove_device(struct generic_pm_domain *genpd,
 int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
 			   struct generic_pm_domain *subdomain)
 {
-	struct gpd_link *link;
+	struct gpd_link *link, *itr;
 	int ret = 0;
 
 	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)
 	    || genpd == subdomain)
 		return -EINVAL;
 
+	link = kzalloc(sizeof(*link), GFP_KERNEL);
+	if (!link)
+		return -ENOMEM;
+
 	mutex_lock(&genpd->lock);
 	mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
 
@@ -1383,18 +1387,13 @@  int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
 		goto out;
 	}
 
-	list_for_each_entry(link, &genpd->master_links, master_node) {
-		if (link->slave == subdomain && link->master == genpd) {
+	list_for_each_entry(itr, &genpd->master_links, master_node) {
+		if (itr->slave == subdomain && itr->master == genpd) {
 			ret = -EINVAL;
 			goto out;
 		}
 	}
 
-	link = kzalloc(sizeof(*link), GFP_KERNEL);
-	if (!link) {
-		ret = -ENOMEM;
-		goto out;
-	}
 	link->master = genpd;
 	list_add_tail(&link->master_node, &genpd->master_links);
 	link->slave = subdomain;
@@ -1496,17 +1495,17 @@  int pm_genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state)
 	if (IS_ERR_OR_NULL(genpd) || state < 0)
 		return -EINVAL;
 
+	cpuidle_data = kzalloc(sizeof(*cpuidle_data), GFP_KERNEL);
+	if (!cpuidle_data)
+		return -ENOMEM;
+
 	mutex_lock(&genpd->lock);
 
 	if (genpd->cpuidle_data) {
 		ret = -EEXIST;
 		goto out;
 	}
-	cpuidle_data = kzalloc(sizeof(*cpuidle_data), GFP_KERNEL);
-	if (!cpuidle_data) {
-		ret = -ENOMEM;
-		goto out;
-	}
+
 	cpuidle_drv = cpuidle_driver_ref();
 	if (!cpuidle_drv) {
 		ret = -ENODEV;