Tips on tracing bwmon?

["Dr. David Alan Gilbert" <dave@treblig.org>]

Hi all,
  I was looking for some tips on if I can use bwmon to see what interconnect
bandwidth is going through the dwc3 usb controllers on my x1 based Asus Zenbook A14.

  I've got usb-ncm gadget wired between a pair of them and I'd
like to see what stats are available;
(See details of my gadget stuff setup in
 https://lore.kernel.org/linux-arm-msm/atJn2jfI_cZy3UMo@gallifrey/T/#u )
And that's struggling to get much over 4Gbit/s over the network interface.

One reason I'm curious is because the dwc3-qcom glue sets an average
and a peak icc limit, and I wanted to know what the difference was and
what the type of timescales were for how long it allowed a peak.

Are there any docs I should look at?

I did:
   trace-cmd stream -e icc_bwmon:qcom_bwmon_update > log
on both machines and during the run I'm seeing events on exactly 3 of the
monitors;
24091000.pmu, 240b5400.pmu, 240b6400.pmu

(In the numbers below I've grepped for that monitor and sed'ed out
upto the 'measu_kbps=' part so I can then sort on the meas_kbps)

My reading of the interconnects_summary is these PMUs are
somewhere under the llcc_mc@interconnect-1, and in some
cases under both chm_apps@  and qns_llcc

So how do I interpret these - can I infer the bandwidth the usb controller
is using or just have a feel for the level above?
(Here the iperf -s server is running on 'dragon' and the client is
running on 'soup' - I find the partial symmetry between 240b[56]400.pmu
on the two machines promising it's measuring something useful!)

This is running a 7.30-rc6 with a bunch of stuff from Jens Glathe
on top.

Thanks in advance,

Dave (numbers below)

24091000.pmu
  on the llcc_mc@interconnect-1 (which also has the a400000.usb)
  
   dragon/server:
        lowest:    16000 up_kbps=800001 down_kbps=800000
       heighest: 2816000 up_kbps=3072001 down_kbps=2188000
        h-l:     2800000         2272000           1388000

   soup/client:
         lowest: 160000 up_kbps=800001 down_kbps=800000
        highest: 6256000 up_kbps=6835201 down_kbps=6220800               
        h-l      6096000         6035200           5420800


240b5400.pmu
  on the chm_apps@26400000.interconnect (which also has the a400000.usb)
        also under qns_llcc@26400000.interconnect
  
    dragon/server:
         lowest: 1328000 up_kbps=4800001 down_kbps=4800000
       heighest: 5616000 up_kbps=7464001 down_kbps=4800000 
            h-l  4288000         2664000                 0

    soup/client:
         lowest: 1440000 up_kbps=4800001 down_kbps=4800000
        highest: 4480000 up_kbps=4800001 down_kbps=4800000
            h-l  3040000               0                 0
                                                          
240b6400.pmu
  same as for 240b5400
  
    dragon/server:
         lowest:  352000 up_kbps=4800001 down_kbps=4800000
        highest: 3568000 up_kbps=4800001 down_kbps=4800000
            h-l  3216000               0                 0

    soup/client:
         lowest: 3216000 up_kbps=4800001 down_kbps=4800000
       heighest: 8736000 up_kbps=9600001 down_kbps=7464000
           h-l   5520000         4800000           2664000

-- 
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