Re: [dpdk-dev] [PATCH v8 4/4] doc/guides/sample_app_ug/l3_forward_power_man.rst: empty poll update

["Liang, Ma" <liang.j.ma@intel.com>]

Hi Dave, 
   thanks for your feedback. I will update document in v9.

O 28 Sep 13:43, Hunt, David wrote:
> Hi Liang,
> 
> 
> I think section 21.4 "Running the Application" needs mention the empty 
> poll feature. Maybe just add a mention
> 
> *   --empty-poll: Traffic Aware power management. See below for details.
> 
> 
> 
> On 25/9/2018 2:20 PM, Kovacevic, Marko wrote:
> >>Add empty poll mode command line example
> >>
> >>Signed-off-by: Liang Ma <liang.j.ma@intel.com>
> >>---
> >>  doc/guides/sample_app_ug/l3_forward_power_man.rst | 29
> >>+++++++++++++++++++++++
> >>  1 file changed, 29 insertions(+)
> >>
> >>+Empty Poll Mode
> >>+-------------------------
> >>+There is a new Mode which is added recently. Empty poll mode can be
> >>+enabled by command option --empty-poll.
> 
> In a couple of years time, it won't be 'new' or 'recent' any more. :)
> 
> Suggest:
> 
> Additionally, there is a traffic aware mode of operation called "Empty
> Poll" where the number of empty polls can be monitored to keep track
> of how busy the application is.Empty poll mode can be enabled by the
> command line option --empty-poll.
> 
> >>+
> >>+See "Power Management" chapter in the DPDK Programmer's Guide for
> >>empty poll mode details.
> >Can you embed the link to the Power Management chapter
> >:doc:`Power Management<../prog_guide/power_man>`
> >
> >
> >>+.. code-block:: console
> >>+
> >>+    ./l3fwd-power -l xxx   -n 4   -w 0000:xx:00.0 -w 0000:xx:00.1 -- -p 
> >>0x3 -P --
> >>config="(0,0,xx),(1,0,xx)" --empty-poll="0,0,0" -l 14 -m 9 -h 1
> >>+
> >>+Where,
> >>+
> >>+--empty-poll: Enable the empty poll mode instead of original algorithm
> >>+
> >>+--empty-poll="training_flag, med_threshold, high_threshold"
> >>+
> >>+* training_flag : optional, enable/disable training mode. Default value 
> >>is 0.
> >>+
> >>+* med_threshold : optional, indicate the empty poll threshold of modest
> >>state which is customized by user. Default value is 0.
> >>+
> >>+* high_threshold : optional, indicate the empty poll threshold of busy 
> >>state
> >>which is customized by user. Default value is 0.
> >>+
> >>+* -l : optional, set up the LOW power state frequency index
> >>+
> >>+* -m : optional, set up the MED power state frequency index
> >>+
> >>+* -h : optional, set up the HIGH power state frequency index
> >I think in this over all section needs a lot more explanation like what 
> >are valid training flags and how to get thresholds ect.
> >
> >Also you could highlight the commands it looks better:      
> >``training_flag``
> 
> I'd suggest adding a "Empty Poll Mode Example Usage" section as a 
> sub-section to the "Empty Poll Mode" section, which could contain 
> something along the lines of the following:
> 
> Empty Poll Mode Example Usage
> 
> To initially obtain the ideal thresholds for the system, the training 
> mode should be run first. This is achieved by running the l3fwd-power 
> app with the training flage set to “1”, and the other paramaters set to 
> 0.
> 
> ./examples/l3fwd-power/build/l3fwd-power -l 1-3 -- -p 0x0f 
> --config="(0,0,2),(0,1,3)" --empty-poll "1,0,0" –P
> 
> This will run the training algorithm for x seconds on each core (cores 2 
> and 3), and then print out the recommended threshold values for those 
> cores. The thresholds should be very similar for each core.
> 
> POWER: Bring up the Timer
> POWER: set the power freq to MED
> POWER: Low threshold is 230277
> POWER: MED threshold is 335071
> POWER: HIGH threshold is 523769
> POWER: Training is Complete for 2
> POWER: set the power freq to MED
> POWER: Low threshold is 236814
> POWER: MED threshold is 344567
> POWER: HIGH threshold is 538580
> POWER: Training is Complete for 3
> 
> Once the values have been measured for a particular system, the app can 
> then be started without the training mode so traffic can start immediately.
> 
> ./examples/l3fwd-power/build/l3fwd-power -l 1-3 -- -p 0x0f 
> --config="(0,0,2),(0,1,3)" --empty-poll "0,340000,540000" –P
> 
> 
>