Solaris CPU run queue

Question

Is there a command which can tell me whats in the Solaris run queue? I can get a count using vmstat, but I need to know what processes/threads are in there.

Answer 1

The run-queue is always changing, so it's almost impossible to get the set of processes in the current run-queue.

That said, you can get an approximation by looking at the STAT (state) field of the process list from ps. When running the command below:

$ ps aux

...the if the STAT field begins with R, then the process is marked RUNNABLE by the kernel, which on most operating systems means that it is in the run-queue. Here's what a runnable process looks like on my machine:

USER       PID %CPU %MEM      VSZ    RSS   TT  STAT STARTED      TIME COMMAND
root     78179   0.0  0.0   599828    480 s003  R+    7:51AM   0:00.00 ps aux

On solaris, you can also use the prstat command and look at the STATE column. The value run indicates that the process is on the run-queue. (Also note that the value cpuN indicates that the process is currently running on processor N.

For example:

$ prstat -s cpu -n 5

PID USERNAME    SIZE    RSS STATE   PRI NICE    TIME    CPU PROCESS/NLWP
13974   kincaid 888K    432K    run 40  0   36:14.51    67% cpuhog/1
27354   kincaid 2216K   1928K   run 31  0   314:48.51   27% server/5
14690   root    136M    46M sleep   59  0   0:00.59 2.3%    Xsun/1
14797   kincaid 9192K   7496K   sleep   59  0   0:00.10 0.9%    dtwm/8
14851   kincaid 24M 14M sleep   48  0   0:00.03 0.3%    netscape/1
Total: 97 processes, 190 lwps, load averages: 2.18, 2.15, 2.11

Answer 2

I was about to correct 0xfe answer when I saw you already did it. The run queue is containing theads not processes so the -L option is mandatory with the prstat command if you want to have the number of "state run" lines more or less matching the run queue. Beware that sampling artifacts will probably prevent to get accurate matches.

In any case, if you want to precisely know what processes/threads are sitting in the run queue you'd rather go the dtrace way assuming you are running Solaris 10 or newer.

The whoqueue.d script which might already been in /usr/demo/dtrace directory on your machine will be a good start:

# dtrace -s /usr/demo/dtrace/whoqueue.d
Run queue of length 1:
  24349/1 (dtrace)
Run queue of length 3:
  0/0 (sched)
  0/0 (sched)
  0/0 (sched)
Run queue of length 4:
  22468/30 (java)
  22468/17 (java)
  22468/23 (java)
  22468/10 (java)

Have a look at this page for details: http://wikis.sun.com/display/DTrace/sched+Provider