Re: process priorities

Dan Hollis (goemon@sasami.anime.net)
Wed, 16 Jul 1997 22:01:34 -0700 (PDT)

On Wed, 16 Jul 1997, Marc Lehmann wrote:
> I always liked that SGI's could easily send jobs into real background..
> their realtime priorities included neagtive numbers which meant
> that these processes have LOWER prioritires than even SCHED_OTHER
> jobs.

Just for the curious, here's a snippet of output from IRIX 6.3 ps:

F S UID PID PPID C PRI NI P SZ:RSS WCHAN TTY TIME CMD
39 S 0 0 0 0 39 RT * 0:0 802a0000 ? 0:01 sched
b9 S 0 2 0 0 39 RT * 0:0 8029f9c0 ? 0:07 vhand
b9 S 0 3 0 0 39 RT * 0:0 8029f628 ? 0:29 bdflush
b9 S 0 4 0 0 25 20 * 0:0 8029fa60 ? 0:00 munldd
b0 S 1000 1147 243 0 60 20 * 449:50 c000033c ? 0:58 fam
b0 R 1000 10556 1294 75 200 BT * 406:46 - pts/1 742:36 rc5v2

'NI' is the scheduling queue the process is in. IRIX has 7, in order of
decreasing priority:

'OS' Kernel
'RT' Real-time (equivalent to Linux's SCHED_FIFO I believe)
'DL' Deadline
'GN' Gang
'TS' Time-share (all normal processes fall here)
'BG' Gang-batch
'BT' Batch (patches were posted to the list recently for this)

-Dan