From owner-freebsd-chat  Fri Apr 16 11: 9:47 1999
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From: "David Schwartz" <davids@webmaster.com>
To: "Daniel C. Sobral" <dcs@newsguy.com>
Cc: <chat@FreeBSD.ORG>
Subject: RE: swap-related problems
Date: Fri, 16 Apr 1999 11:07:22 -0700
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> >         So long before critical processes can starve
> non-critical processes, the
> > reverse will occur.
>
> Ah, I see... you have a kind of point. You will find out, though,
> that no critical process will run, because the non-critical ones
> will long have overcommitted.

	There might be a demand for, for example, separate swap for critical and
non-critical processes. Or there may be a wish to reserve a certain amount
of swap just for critical processes, or to require overcommittment to exceed
a certain amount before 'critical' processes have their allocations fail.

	This is a tuning question. It's easily possible to err in either direction.

	The point is, however, that a well-behaved process can't behave well
without adequate feedback. And a fully-overcommitting kernel generally can't
provide that feedback. A never-overcommitting kernel can, but unfortunately,
that simply requires too much swap. Surely a reasonable compromise can be
struck.

	DS



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