swapper and sched daemon

[Amit Dixit_2]

HI,
Can anyone explain the what does the swapper
daemon do and what is sched daemon for ?

And In solaris doeas the sched daemon always
has the PID 0, why swapper is is having PID
0 on HP-UX is it a constant ?

Thanks,
Amit

[Jose Mosquera]

Hi,

Pls check attachment.

Rgds.

[David Child_1]

From HP documentation:

"Two computational elements maintain page availability:
· Paging thresholds trigger the gamut of paging events.
· The vhand and sched daemons (system processes) handle the actual paging and deactivation.

vhand monitors free pages to keep their number above a threshold and ensure sufficient memory for demand paging. vhand governs the overall state of the paging system. sched becomes operative when the number of pages available in memory diminishes below a certain level. vhand and sched will be described in the context of their work shortly.
NOTE: The sched process is known colloquially as the swapper

[Steven E. Protter]

Interesting thread on the topic.

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=206881

An old document that probably explains how a PID can be zero.

http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/5965-4642/5965-4642_top.html&con=/hpux/onlinedocs/5965-4642/00/00/5-con.html&toc=/hpux/onlinedocs/5965-4642/00/00/5-toc.html&searchterms=sched%7cswapper&queryid=20040927-102132

SEP

[Amit Dixit_2]

Hi,
Can anyone explain which daemon on HP and
on solaris takes care of process
monitoring

i.e. which process should utilize CPU and
when ?
can anyone tell the name of the daemon for
both the O.S.

[Jose Mosquera]

Hi again,

Take a look here:
http://www.unixguide.net/cgi-bin/unixguide.cgi

Rgds.