A question I received this week from a customer.

 

Hi Chris,

 

Is there  a way to find on which processor a process is executing?

 

If I’ve used binprocessor, ps –emo THREAD, would show which processor a process is bound too. But when that’s not been used, what are the options?

 

The ps command will only help if we bind a process to a specific CPU. For example, here we can see that the bootpd process has been bound (and then un-bound) on processor 3:

 

# bindprocessor -q

The available processors are:  0 1 2 3

 

# bindprocessor 8585302 3

 

# ps -o THREAD -p 8585302

    USER     PID    PPID       TID ST  CP PRI SC    WCHAN        F     TT BND COMMAND

    root 8585302 4063394         - A    0  60  1        -   200001      -   3 bootpd /etc/bootptab

 

# bindprocessor -u 8585302

 

# ps -o THREAD -p 8585302

    USER     PID    PPID       TID ST  CP PRI SC    WCHAN        F     TT BND COMMAND

    root 8585302 4063394         - A    0  60  1        -   200001      -   - bootpd /etc/bootptab

 

The trace command will tell us what CPU a process is scheduled on.*

 

# /usr/bin/trace –J’curt' -P'p' '-a'

 

# sleep 30

 

# trcstop

 

# trcrpt -O'exec=y' -O'pid=n' -O'tid=n' -O'wparname=off' -O'cid=off' -O'svc=y' -O'timestamp=1'  | /usr/lib/ras/trace_smutil cat Z'/tmp/trace.out'

 

# vi /tmp/trace.out                 (I’m interested in PID 904428 in this case)

 

106  ksh 0.033107          dispatch:   cmd=ksh pid=9044208 tid=9175205 priority=135 old_tid=9175205 old_priority=135 CPUID=2 [302 usec]

101D ksh 0.033108                   Home SRAD=-1 Home ref1=-1 Dispatch SRAD=-1 Dispatch ref1=-1

200  ksh 0.033108                   resume  ksh iar=100180CC cpuid=02

 

 

 

*Note: If you are running AIX 5.3 try these options with trcrpt (tested on an AIX 5.3 TL11 SP3 system):

 

# trcrpt -O'exec=y' -O'pid=n' -O'tid=n' -O'svc=y' -O'timestamp=1'  | /usr/lib/ras/trace_smutil cat Z'/tmp/trace.out'

 

Perhaps there are other methods of monitoring this type of activity online, rather than offline?

 

 

 

Tags:  trace gibson chris curt aix