Hi Kevin,
On 27/6/2018 6:33 PM, Kevin Traynor wrote:
On 06/26/2018 12:40 PM, Radu Nicolau wrote:
From: Liang Ma <liang.j...@intel.com>
1. Abstract
--snip--
2.2 There are two phases to establish the power management system:
a.Initialization/Training phase. There is no traffic pass-through,
the system will test average empty poll numbers with
LOW/MED/HIGH power state. Those average empty poll numbers
will be the baseline
for the normal phase. The system will collect all core's counter
every 100ms. The Training phase will take 5 seconds.
This is requiring an application to sit for 5 secs in order to train and
align poll numbers with states? That doesn't seem realistic to me.
Thanks for the discussion at DPDK Userspace conference. Since we got
back, Liang and
I have discussed the feedback we received, and we have a proposal.
We can split out the training phase into a separate run of the application
which does the training, spits out the threshold numbers, and then
the actual runs will start instantly once the threshold parameters are
provided on the command line, or falls back to hard-coded defaults if
no command line parameters are given.
So there are three ways of running the app
1. Run without any threshold parameters, in which case the algorithm
runs with default numbers calculated based on the min and max
available frequency.
2. Run with --train option, which requires no traffic on the NICS, and
runs the training algorithm, prints out the thresholds for the
host CPU, and exits.
3. Take the output of the train phase, and provide the thresholds on
the command
line, and the app runs with the best fit to the running CPU.
That would eliminate the training period at startup, unless the user
wanted to fine-tune
for a particular host CPU.
Would that be an adequate solution to the training period concerns?
Regards,
Dave.
