pdpd running on an SND core?

[kamilazat]

Hi everyone. 

We're baffled with a situation where we see the pdpd daemon running on an SND core. 

We first get the core that the pdpd is running:

[Expert0]# ps aux | grep pdpd
admin     54777 51.1  1.0 1915608 1423476 ?     Sl   Jul07 12620:16 pdpd 0 -t
admin    181696  0.0  0.0   2652   572 pts/6    S+   01:23   0:00 grep --color=auto pdpd

[Expert0]# ps -o pid,comm,psr -p 54777
   PID COMMAND         PSR
 54777 pdpd              1

After seeing that it is running on CPU 1, we check the fwaffinity to see what that core is.

[Expert0]# fw ctl affinity -l -a -v -r
no stats available
no stats available
no stats available
no stats available
no stats available
no stats available
no stats available
no stats available
no stats available
no stats available
no stats available
no stats available
no stats available
CPU 0 :
CPU 1 :
CPU 2 :
CPU 3 :
CPU 4 :
CPU 5 :
CPU 6 :
CPU 7 :
CPU 8 : fw_30 (active)fw_31fw_32fw_33fw_34fw_35fw_36fw_37fw_38fw_39fw_40fw_41fw_42
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 9 : fw_28 (active)fw_31fw_32fw_33fw_34fw_35fw_36fw_37fw_38fw_39fw_40fw_41fw_42
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 10: fw_26 (active)fw_31fw_32fw_33fw_34fw_35fw_36fw_37fw_38fw_39fw_40fw_41fw_42
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 11: fw_24 (active)fw_31fw_32fw_33fw_34fw_35fw_36fw_37fw_38fw_39fw_40fw_41fw_42
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 12:
CPU 13:
CPU 14:
CPU 15:
CPU 16:
CPU 17:
CPU 18:
CPU 19: fw_8 (active)fw_9fw_10fw_11fw_12fw_13fw_14fw_15fw_16fw_17fw_18fw_19fw_20fw_21fw_22
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 20: fw_6 (active)fw_9fw_10fw_11fw_12fw_13fw_14fw_15fw_16fw_17fw_18fw_19fw_20fw_21fw_22
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 21: fw_4 (active)fw_9fw_10fw_11fw_12fw_13fw_14fw_15fw_16fw_17fw_18fw_19fw_20fw_21fw_22
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 22: fw_2 (active)fw_9fw_10fw_11fw_12fw_13fw_14fw_15fw_16fw_17fw_18fw_19fw_20fw_21fw_22
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 23: fw_0 (active)fw_9fw_10fw_11fw_12fw_13fw_14fw_15fw_16fw_17fw_18fw_19fw_20fw_21fw_22
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 24:
CPU 25:
CPU 26:
CPU 27:
CPU 28:
CPU 29:
CPU 30:
CPU 31:
CPU 32: fw_29 (active)fw_31fw_32fw_33fw_34fw_35fw_36fw_37fw_38fw_39fw_40fw_41fw_42
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 33: fw_27 (active)fw_31fw_32fw_33fw_34fw_35fw_36fw_37fw_38fw_39fw_40fw_41fw_42
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 34: fw_25 (active)fw_31fw_32fw_33fw_34fw_35fw_36fw_37fw_38fw_39fw_40fw_41fw_42
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 35: fw_23 (active)fw_31fw_32fw_33fw_34fw_35fw_36fw_37fw_38fw_39fw_40fw_41fw_42
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 36:
CPU 37:
CPU 38:
CPU 39:
CPU 40:
CPU 41:
CPU 42:
CPU 43: fw_7 (active)fw_9fw_10fw_11fw_12fw_13fw_14fw_15fw_16fw_17fw_18fw_19fw_20fw_21fw_22
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 44: fw_5 (active)fw_9fw_10fw_11fw_12fw_13fw_14fw_15fw_16fw_17fw_18fw_19fw_20fw_21fw_22
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 45: fw_3 (active)fw_9fw_10fw_11fw_12fw_13fw_14fw_15fw_16fw_17fw_18fw_19fw_20fw_21fw_22
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 46: fw_1 (active)fw_9fw_10fw_11fw_12fw_13fw_14fw_15fw_16fw_17fw_18fw_19fw_20fw_21fw_22
        cprid mpdaemon lpd in.ahclientd core_uploader in.asessiond vpnd pdpd pepd cprid cpd msgd
CPU 47: fwd
All:
Interface ethsBP1-02: has multi queue enabled
Interface ethsBP1-01: has multi queue enabled

At first we thought that maybe dynamic balancing is dynamically playing with the SND cores and that may be why, but we also see this output at night where there is very little traffic that may trigger core switching between FW and SND. 

Is this a normal thing?

Cheers!

[Timothy_Hall]

What hardware and code is this?  Using VSX or not?  Maestro?

It almost resembles open hardware, with 8 physical cores and 4 threads per core.  Since a core is assigned for fwd, I'm assuming you are using R81.20, as this static assignment no longer occurs in R82+.

[kamilazat]

Hi Tim. I guess I masked the user a bit too much.

It's Maestro R81.10 JHT 172. Output is from SMO.

[Timothy_Hall]

Hardware?

[kamilazat]

Not sure, but it's 16600 if I recall correctly.

[Timothy_Hall]

I don't think core 1 where pdpd is executing is an SND core. What does the CPU...Overview screen of cpview say is the current CoreXL split?  (you may need to enlarge your command window to see all cores) I highly doubt it is 30/17 unless you have a huge amount of fastpath traffic due to no Deep Inspection blades being enabled.