[dpdk-dev] [PATCH v2 0/8] examples/vm_power: 100% Busy Polling

[Radu Nicolau]

On 6/21/2018 2:24 PM, David Hunt wrote:
> This patch set adds the capability to do out-of-band power
> monitoring on a system. It uses a thread to monitor the branch
> counters in the targeted cores, and calculates the branch ratio
> if the running code.
>
> If the branch ratop is low (0.01), then
> the code is most likely running in a tight poll loop and doing
> nothing, i.e. receiving no packets. In this case we scale down
> the frequency of that core.
>
> If the branch ratio is higher (>0.01), then it is likely that
> the code is receiving and processing packets. In this case, we
> scale up the frequency of that core.
>
> The cpu counters are read via /dev/cpu/x/msr, so requires the
> msr kernel module to be loaded. Because this method is used,
> the patch set is implemented with one file for x86 systems, and
> another for non-x86 systems, with conditional compilation in
> the Makefile. The non-x86 functions are stubs, and do not
> currently implement any functionality.
>
> The vm_power_manager app has been modified to take a new parameter
>     --core-list or -l
> which takes a list of cores in a comma-separated list format,
> e.g. 1,3,5-7,9, which resolvest to a core list of 1,3,5,6,7,9
> These cores will then be enabled for oob monitoring. When the
> OOB monitoring thread starts, it reads the branch hits/miss
> counters of each monitored core, and scales up/down accordingly.
>
> The guest_cli app has also been modified to allow sending of a
> policy of type BRANCH_RATIO where all of the cores included in
> the policy will be monitored by the vm_power_manager oob thread.
>
> v2 changes:
>     * Add the guest_cli patch into this patch set, including the
>       ability to set the policy to BRANCH_RATIO.
>       http://patches.dpdk.org/patch/40742/
>     * When vm_power_manger receives a policy with type BRANCH_RATIO,
>       add the relevant cores to the monitoring thread.
>
> [1/8] examples/vm_power: add check for port count
> [2/8] examples/vm_power: add core list parameter
> [3/8] examples/vm_power: add oob monitoring functions
> [4/8] examples/vm_power: allow greater than 64 cores
> [5/8] examples/vm_power: add thread for oob core monitor
> [6/8] examples/vm_power: add port-list to command line
> [7/8] examples/vm_power: add branch ratio policy type
> [8/8] examples/vm_power: add cli args to guest app
>
Series Acked-by: Radu Nicolau <radu.nicolau at intel.com>