Preallocate a buffer for the response to sensor reads, and reuse it
for each read instead of allocating a new one each time. This should
be faster and should also avoid memory fragmentation.
Signed-off-by: Jean Delvare <khali@xxxxxxxxxxxx>
Cc: Darrick J. Wong <djwong@xxxxxxxxxx>
Cc: Guenter Roeck <guenter.roeck@xxxxxxxxxxxx>
---
Darrick, can you please test this patch and report? I do not have the
hardware.
drivers/hwmon/ibmaem.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
--- linux-3.1-rc2.orig/drivers/hwmon/ibmaem.c 2011-08-18 19:16:12.000000000 +0200
+++ linux-3.1-rc2/drivers/hwmon/ibmaem.c 2011-08-18 19:31:36.000000000 +0200
@@ -148,8 +148,9 @@ struct aem_data {
int id;
struct aem_ipmi_data ipmi;
- /* Function to update sensors */
+ /* Function and buffer to update sensors */
void (*update)(struct aem_data *data);
+ struct aem_read_sensor_resp *rs_resp;
/*
* AEM 1.x sensors:
@@ -390,13 +391,14 @@ static void aem_idr_put(int id)
/* Sensor support functions */
-/* Read a sensor value */
+/* Read a sensor value; must be called with data->lock held */
static int aem_read_sensor(struct aem_data *data, u8 elt, u8 reg,
void *buf, size_t size)
{
int rs_size, res;
struct aem_read_sensor_req rs_req;
- struct aem_read_sensor_resp *rs_resp;
+ /* Use preallocated rx buffer */
+ struct aem_read_sensor_resp *rs_resp = data->rs_resp;
struct aem_ipmi_data *ipmi = &data->ipmi;
/* AEM registers are 1, 2, 4 or 8 bytes */
@@ -422,9 +424,6 @@ static int aem_read_sensor(struct aem_da
ipmi->tx_message.data_len = sizeof(rs_req);
rs_size = sizeof(*rs_resp) + size;
- rs_resp = kzalloc(rs_size, GFP_KERNEL);
- if (!rs_resp)
- return -ENOMEM;
ipmi->rx_msg_data = rs_resp;
ipmi->rx_msg_len = rs_size;
@@ -468,7 +467,6 @@ static int aem_read_sensor(struct aem_da
res = 0;
out:
- kfree(rs_resp);
return res;
}
@@ -526,6 +524,7 @@ static void aem_delete(struct aem_data *
{
list_del(&data->list);
aem_remove_sensors(data);
+ kfree(data->rs_resp);
hwmon_device_unregister(data->hwmon_dev);
ipmi_destroy_user(data->ipmi.user);
platform_set_drvdata(data->pdev, NULL);
@@ -618,6 +617,11 @@ static int aem_init_aem1_inst(struct aem
}
data->update = update_aem1_sensors;
+ data->rs_resp = kzalloc(sizeof(*(data->rs_resp)) + 8, GFP_KERNEL);
+ if (!data->rs_resp) {
+ res = -ENOMEM;
+ goto alloc_resp_err;
+ }
/* Find sensors */
res = aem1_find_sensors(data);
@@ -633,6 +637,8 @@ static int aem_init_aem1_inst(struct aem
return 0;
sensor_err:
+ kfree(data->rs_resp);
+alloc_resp_err:
hwmon_device_unregister(data->hwmon_dev);
hwmon_reg_err:
ipmi_destroy_user(data->ipmi.user);
@@ -753,6 +759,11 @@ static int aem_init_aem2_inst(struct aem
}
data->update = update_aem2_sensors;
+ data->rs_resp = kzalloc(sizeof(*(data->rs_resp)) + 8, GFP_KERNEL);
+ if (!data->rs_resp) {
+ res = -ENOMEM;
+ goto alloc_resp_err;
+ }
/* Find sensors */
res = aem2_find_sensors(data);
@@ -768,6 +779,8 @@ static int aem_init_aem2_inst(struct aem
return 0;
sensor_err:
+ kfree(data->rs_resp);
+alloc_resp_err:
hwmon_device_unregister(data->hwmon_dev);
hwmon_reg_err:
ipmi_destroy_user(data->ipmi.user);
--
Jean Delvare
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