Allocating the sysfs attribute name only if needed and only with the
required minimum length looks optimal, but does not take the additional
overhead for both devm_ data structures and the allocation header itself
into account. This also results in unnecessary memory fragmentation.
Move the sysfs name string into struct hwmon_device_attribute and give it
a sufficient length to reduce this overhead.
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
drivers/hwmon/hwmon.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index 58c328f4508d..3932f9276c07 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -38,12 +38,15 @@ struct hwmon_device {
#define to_hwmon_device(d) container_of(d, struct hwmon_device, dev)
+#define MAX_SYSFS_ATTR_NAME_LENGTH 32
+
struct hwmon_device_attribute {
struct device_attribute dev_attr;
const struct hwmon_ops *ops;
enum hwmon_sensor_types type;
u32 attr;
int index;
+ char name[MAX_SYSFS_ATTR_NAME_LENGTH];
};
#define to_hwmon_attr(d) \
@@ -261,20 +264,18 @@ static struct attribute *hwmon_genattr(struct device *dev,
if ((mode & S_IWUGO) && !ops->write)
return ERR_PTR(-EINVAL);
+ hattr = devm_kzalloc(dev, sizeof(*hattr), GFP_KERNEL);
+ if (!hattr)
+ return ERR_PTR(-ENOMEM);
+
if (type == hwmon_chip) {
name = (char *)template;
} else {
- name = devm_kzalloc(dev, strlen(template) + 16, GFP_KERNEL);
- if (!name)
- return ERR_PTR(-ENOMEM);
- scnprintf(name, strlen(template) + 16, template,
+ scnprintf(hattr->name, sizeof(hattr->name), template,
index + hwmon_attr_base(type));
+ name = hattr->name;
}
- hattr = devm_kzalloc(dev, sizeof(*hattr), GFP_KERNEL);
- if (!hattr)
- return ERR_PTR(-ENOMEM);
-
hattr->type = type;
hattr->attr = attr;
hattr->index = index;
--
2.5.0
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