From: Liang Ma <liang.j...@intel.com>
Update programmer's guide to document PMD power management usage.
Signed-off-by: Liang Ma <liang.j...@intel.com>
Signed-off-by: Anatoly Burakov <anatoly.bura...@intel.com>
Acked-by: David Hunt <david.h...@intel.com>
---
Notes:
v5:
- Moved l3fwd-power update to the l3fwd-power-related commit
- Some rewordings and clarifications
doc/guides/prog_guide/power_man.rst | 42 +++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
diff --git a/doc/guides/prog_guide/power_man.rst
b/doc/guides/prog_guide/power_man.rst
index 0a3755a901..38c64d31e4 100644
--- a/doc/guides/prog_guide/power_man.rst
+++ b/doc/guides/prog_guide/power_man.rst
@@ -192,6 +192,45 @@ User Cases
----------
The mechanism can applied to any device which is based on polling. e.g. NIC,
FPGA.
+PMD Power Management API
+------------------------
+
+Abstract
+~~~~~~~~
+Existing power management mechanisms require developers to change application
+design or change code to make use of it. The PMD power management API provides
a
+convenient alternative by utilizing Ethernet PMD RX callbacks, and triggering
+power saving whenever empty poll count reaches a certain number.
+
+ * UMWAIT/UMONITOR
+
+ This power saving scheme will put the CPU into optimized power state and use
+ the UMWAIT/UMONITOR instructions to monitor the Ethernet PMD RX descriptor
+ address, and wake the CPU up whenever there's new traffic.
+
+ * Pause
+
+ This power saving scheme will use the `rte_pause` function to avoid busy
+ polling.
+
+ * Frequency scaling
+
+ This power saving scheme will use existing power library functionality to
+ scale the core frequency up/down depending on traffic volume.
+
+
+.. note::
+
+ Currently, this power management API is limited to mandatory mapping of 1
+ queue to 1 core (multiple queues are supported, but they must be polled from
+ different cores).
+
+API Overview for PMD Power Management
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+* **Queue Enable**: Enable specific power scheme for certain queue/port/core
+
+* **Queue Disable**: Disable power scheme for certain queue/port/core
+
References
----------
@@ -200,3 +239,6 @@ References
* The :doc:`../sample_app_ug/vm_power_management`
chapter in the :doc:`../sample_app_ug/index` section.
+
+* The :doc:`../sample_app_ug/rxtx_callbacks`
+ chapter in the :doc:`../sample_app_ug/index` section.
--
2.17.1
