Subject: Re: Virtual Memory Subsystem
To: None <port-i386@NetBSD.ORG>
From: Mister Gandalf <mgandalf@Mentasm.com>
List: port-i386
Date: 11/25/1996 23:14:34
On Tue, 26 Nov 1996 14:55:13 +1100,
Stephen.Ma@jtec.com.au (Stephen Ma) wrote about Virtual Memory Subsystem=
:
> >>>>> "Mister" =3D=3D Mister Gandalf <mgandalf@Mentasm.com> writes:
>=20
> Mister> I have noticed that ever since I've installed NetBSD (over a
> Mister> year ago) that the kernel never returns swap space to me.
> Mister> Whenever I go into swap, that amount used stays used until I
> Mister> reboot the system.
>=20
> This is the well-known "swap-leak" bug. What happens is that swap
> space allocated to a VM object is never deallocated until the VM
> object is destroyed. Thus, when part of a daemon is paged out, and
> paged back in again, the swap space allocated remains allocated to
> that daemon, even though that daemon doesn't need it after being paged=

> back in. Since daemons don't exit at all, the swap space is never
> reclaimed. (actually, the swap space can be reclaimed by going to
> single user mode - you should notice used swap space going back to 0
> after a "shutdown now").
>=20
> A fix for this is probably a long way off...
>=20
> - S
>=20
>=20

I would have thought this would be fixed by now.  I consider this a majo=
r
issue and reason enough to switch to another OS, and I'm sure many other=

people think this as well.

-- Mark.

------------------------------------------------------------------------=
--
              Straight from the FOREVER crashing computer!

                              Mentasm FTP
                           HTTP coming soon!
              A3000, 68040/40mhz, 54megs, 3.1gig, Ethernet

                  CLCHAT SERVER!  us4.clchat.vapor.com

                         Mac, Unix, PC, Amiga
------------------------------------------------------------------------=
--