[Crash-utility] patch for slight modification to runq -g command

[Dave Anderson]

----- Original Message -----
>
> The "runq -g" output for that cpu looks like this:
> 
>   CPU 1
>     CURRENT: PID: 1212  CFS: ffff880035cc2f00 TASK: ffff880035f60000
>     COMMAND: "bash"
>     TASK_GROUP RT_RQ: ffff88007fa541e8
>     RT PRIO_ARRAY: ffff88007fa541e8
>        [no tasks queued]
>     TASK_GROUP CFS_RQ: ffff88007fa540f0
>     CFS RB_ROOT: ffff88007fa54118
>        GROUP: ffff880078af7800 CFS_RQ: ffff880035cc2f00 RB_ROOT: ffff880035cc2f28 nr_running: 4294967297 h_nr_running: 201908650262921217
>           [120] PID: 1212   TASK: ffff880035f60000  COMMAND: "bash"
>   
> I don't understand where those values are coming from, because if
> I look at the CFS_RQ, it shows this:
> 
>   crash> cfs_rq.nr_running,h_nr_running ffff880035cc2f00
>     nr_running = 1
>     h_nr_running = 1
>   crash>

The problem above is due to the fact that both nr_running and h_nr_running
are of type unsigned int but your patch reads each of them as a ulong:

 crash> eval 4294967297
 hexadecimal: 100000001  
     decimal: 4294967297  
       octal: 40000000001
      binary: 0000000000000000000000000000000100000000000000000000000000000001
 crash> eval 201908650262921217
 hexadecimal: 2cd52d900000001  
     decimal: 201908650262921217  
       octal: 13152455440000000001
      binary: 0000001011001101010100101101100100000000000000000000000000000001
 crash>

+       readmem(cfs_rq + OFFSET(cfs_rq_nr_running), KVADDR,
+               &nr_running, sizeof(ulong), "cfs_rq nr_running",
+               FAULT_ON_ERROR);
+       if (VALID_MEMBER(cfs_rq_h_nr_running)) {
+               readmem(cfs_rq + OFFSET(cfs_rq_h_nr_running), KVADDR,
+                       &h_nr_running, sizeof(ulong), "cfs_rq h_nr_running",
+                       FAULT_ON_ERROR);
+               fprintf(fp, " nr_running: %lu h_nr_running: %lu ", nr_running, h_nr_running);
+       } else {
+               fprintf(fp, " nr_running: %lu ", nr_running);
+       }

But again, I don't seen any compelling reason to display them at all -- especially
now that your patch displays the cfs_rq from which they come.  If you really
need to see their values, just dump the data structure.

And as I mentioned earlier, the CFS address in the CURRENT: line is confusing and
redundant.  Perhaps you could clarify things by appending "[CURRENT]" after
the task identifier in the queue, i.e., like:

    [120] PID: 9048   TASK: ffff8808b07e4200  COMMAND: "actmain"  [CURRENT]

Thanks,
  Dave