'ps' behavoir in Linux - Was - Re: array limits

[Jay R. Ashworth]

On Sat, Apr 17, 2004 at 09:58:14AM -0400, Fairlight wrote:
> He would be able to see cmdline's contents as any user--IF the process is
> not swapped out.  If it's swapped out, you're out of luck.  I don't know a
> way to force a program to be swapped back in besides having it in a
> non-sleeping state and keeping it that way.

Send it a signal you know it has an IGNORE handler for.  I'm pretty
sure it has to swap it in to find out.  And I'm pretty sure there's at
least one signal that defaults to IGNOR.

> I've been through the /proc tree a few times over the course of this
> thread, and Jay's pointing out the swap-out nomenclature of ps's output
> definitely pointed the way towards this conclusion.  I've tested -every-
> process notated as [program] in the 'ps' listing, and I can't get anything
> from cmdline on any of them.  Then there's 'init', which is -not- swapped
> out, and I can get the single word 'init' out of cmdline for PID 1.  I
> can't get anything out of anything that's swapped.

You can pass arguments to init, from the boot prompt, but it's not real
common.

> It's definitely puzzling to me as to how and why dclerk is swapped out.
> The only things that are really like that on my systems are things like
> kflushd, kupdate, the multiple device drivers (software RAID, etc.), and
> things like lockd and rpciod.  And this is on systems that have been using
> swap. 
> 
> I don't honestly recall ever seeing dclerk swapped and sleeping like that
> on -any- platform.  Very strange.

Depends on what's goinon.  I have a VNC/KDE system with 8 running Xvnc
servers, 640MB RAM plus about 400MB swap at any given time.

It's actually not bad; they have *so much* stuff running on desktops
that aren't active that the swap-in time isn't too painful.  Anyone
know if Dell Precision 410's will take 512MB DIMMs?

Cheers,
-- jra
-- 
Jay R. Ashworth                                                jra at baylink.com
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