diff options
| author | Darrick J. Wong <djwong@us.ibm.com> | 2008-08-15 11:40:41 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-08-15 19:35:44 +0400 |
| commit | bb15e7f286e3ecf3e85e06ad9b0019096e43a613 (patch) | |
| tree | 88fd7cb042f3477699cb05c780518dc7dc1ed5a5 /drivers/hwmon | |
| parent | 9c5413eac5199b8457689eb2c9d9e75138356bd6 (diff) | |
| download | linux-bb15e7f286e3ecf3e85e06ad9b0019096e43a613.tar.xz | |
ibmaem: don't query the entire sensor repository when reading energy meter
Currently, all sensors are read when the energy meter is queried via
sysfs. This introduces a considerable amount of delay and variation in
the sysfs reading, which is not desirable when trying to profile energy
use. Therefore, read only the energy meters when a sysfs query comes in
for them, and don't cache the results so that we always get the latest
reading.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/hwmon')
| -rw-r--r-- | drivers/hwmon/ibmaem.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/drivers/hwmon/ibmaem.c b/drivers/hwmon/ibmaem.c index 08c5179e6d84..0f70dc204105 100644 --- a/drivers/hwmon/ibmaem.c +++ b/drivers/hwmon/ibmaem.c @@ -463,12 +463,18 @@ static int aem_read_sensor(struct aem_data *data, u8 elt, u8 reg, } /* Update AEM energy registers */ +static void update_aem_energy_one(struct aem_data *data, int which) +{ + aem_read_sensor(data, AEM_ENERGY_ELEMENT, which, + &data->energy[which], 8); +} + static void update_aem_energy(struct aem_data *data) { - aem_read_sensor(data, AEM_ENERGY_ELEMENT, 0, &data->energy[0], 8); + update_aem_energy_one(data, 0); if (data->ver_major < 2) return; - aem_read_sensor(data, AEM_ENERGY_ELEMENT, 1, &data->energy[1], 8); + update_aem_energy_one(data, 1); } /* Update all AEM1 sensors */ @@ -850,7 +856,7 @@ static ssize_t aem_show_power(struct device *dev, struct timespec b, a; mutex_lock(&data->lock); - update_aem_energy(data); + update_aem_energy_one(data, attr->index); getnstimeofday(&b); before = data->energy[attr->index]; @@ -862,7 +868,7 @@ static ssize_t aem_show_power(struct device *dev, return 0; } - update_aem_energy(data); + update_aem_energy_one(data, attr->index); getnstimeofday(&a); after = data->energy[attr->index]; mutex_unlock(&data->lock); @@ -881,7 +887,9 @@ static ssize_t aem_show_energy(struct device *dev, { struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); struct aem_data *a = dev_get_drvdata(dev); - a->update(a); + mutex_lock(&a->lock); + update_aem_energy_one(a, attr->index); + mutex_unlock(&a->lock); return sprintf(buf, "%llu\n", (unsigned long long)a->energy[attr->index] * 1000); |