| commit | 6d50c3e9e184d3741eec13bd164518864fe806bf | [log] [tgz] |
|---|---|---|
| author | Brandon Kim <brandonkim@google.com> | Fri Aug 09 15:38:53 2019 -0700 |
| committer | Brandon Kim <brandonkim@google.com> | Fri May 07 19:09:11 2021 +0000 |
| tree | 3de9c83d73bb51dbd1514145fd3380799bc5563f | |
| parent | d46d081895ada3ab411996dc3a681f796f4a0926 [diff] |
sensor: Implement sensor "ASYNC_READ_TIMEOUT"
This change will prevent sensors from blocking all other sensor reads
and D-Bus if they do not report failures quickly enough.
If "ASYNC_READ_TIMEOUT" environment variable is defined in the
sensor's config file for a key_type, the sensor read will be
asynchronous with timeout set in milliseconds.
For example for "sensor1":
ASYNC_READ_TIMEOUT_sensor1="1000" // Timeout will be set to 1 sec
If the read times out, the sensor read will be skipped and the
sensor's functional property will be set to 'false'. Timed out futures
will be placed in a map to prevent their destructor from running and
blocking until the read completes (limitation of std::async).
Tested: This patch has been running downstream for over a year to
solve a slow I2C sensor reads causing IPMI slowdown.
Change-Id: I3d9ed4d5c9cc87d3196fc281451834f3001d0b48
Signed-off-by: Brandon Kim <brandonkim@google.com>
Exposes generic hwmon entries as DBus objects. More information can be found at Sensor Architecture
To build this package, do the following steps:
1. meson build
2. ninja -C build
To clean the repository run `rm -rf build`.
To enable the use of Linux features like cgroups prioritization and udev/systemd control, one instance of phosphor-hwmon is intended to be run per hwmon sysfs class instance. This requires an algorithm for selecting a stable, well-known D-Bus busname. The algorithm is <PREFIX>-<ID>.Hwmon<N> where PREFIX is an autoconf configurable prefix (BUSNAME_PREFIX, xyz.openbmc_project by default), ID is either a std::hash of the /sys/devices path backing the hwmon class instance or provided suffix value from the command line, and N is the implemented phosphor-hwmon D-Bus API version.