[dpdk-dev] [PATCH v17 07/11] power: add PMD power management API and callback

[David Hunt]

Hi Anatoly,

On 14/1/2021 2:46 PM, Anatoly Burakov wrote:
> From: Liang Ma <liang.j.ma at intel.com>
>
> Add a simple on/off switch that will enable saving power when no
> packets are arriving. It is based on counting the number of empty
> polls and, when the number reaches a certain threshold, entering an
> architecture-defined optimized power state that will either wait
> until a TSC timestamp expires, or when packets arrive.
>
> This API mandates a core-to-single-queue mapping (that is, multiple
> queued per device are supported, but they have to be polled on different
> cores).
>
> This design is using PMD RX callbacks.
>
> 1. UMWAIT/UMONITOR:
>
>     When a certain threshold of empty polls is reached, the core will go
>     into a power optimized sleep while waiting on an address of next RX
>     descriptor to be written to.
>
> 2. TPAUSE/Pause instruction
>
>     This method uses the pause (or TPAUSE, if available) instruction to
>     avoid busy polling.
>
> 3. Frequency scaling
>     Reuse existing DPDK power library to scale up/down core frequency
>     depending on traffic volume.
>
> Signed-off-by: Liang Ma <liang.j.ma at intel.com>
> Signed-off-by: Anatoly Burakov <anatoly.burakov at intel.com>
> ---
>
> Notes:
>      v17:
>      - Added memory barriers suggested by Konstantin
>      - Removed the BUSY state
>
>   doc/guides/prog_guide/power_man.rst    |  44 +++
>   doc/guides/rel_notes/release_21_02.rst |  10 +
>   lib/librte_power/meson.build           |   5 +-
>   lib/librte_power/rte_power_pmd_mgmt.c  | 364 +++++++++++++++++++++++++
>   lib/librte_power/rte_power_pmd_mgmt.h  |  90 ++++++
>   lib/librte_power/version.map           |   5 +
>   6 files changed, 516 insertions(+), 2 deletions(-)
>   create mode 100644 lib/librte_power/rte_power_pmd_mgmt.c
>   create mode 100644 lib/librte_power/rte_power_pmd_mgmt.h
>

Acked-by: David Hunt <david.hunt at intel.com>