Subject: kern/25339: VM subsystem broken.
To: None <>
From: Denis Lagno <>
List: netbsd-bugs
Date: 04/27/2004 01:18:41
>Number:         25339
>Category:       kern
>Synopsis:       starting jobs that allocates big chunks of swappable memory can hang up system
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Apr 26 21:19:00 UTC 2004
>Originator:     Denis Lagno
>Release:        NetBSD 2.0E (Apr 25 snapshot)
System: NetBSD flamante.local.domain 2.0E NetBSD 2.0E (FLAMANTE) #0: Mon Apr 26 12:34:19 MSD 2004 dina@flamante.local.domain:/var/worksrc/netbsd-current/src/sys/arch/i386/compile/FLAMANTE i386
Architecture: i386
Machine: i386
Earlier I filed PR kern/25315 "reproducible hangups when creating virtual screens in screen(1)"
I discovered that real reason of hangups was somewhere in swap subsystem.
Hangups occur always when I use swap (I use swap on cgd but swap on normal device
hangs as well) and have jobs allocating big chunks of memory.
Recently I bumped size of scrollback buffer in screen from 10000 to 100000 lines
so screen was such job in my case.
have some swap attached.
start some memory consuming activity.
Observe hangup.