Subject: kern/26878: FFSv2 + softdep = livelock (no free ram)
To: None <>
From: Richard Earnshaw <>
List: netbsd-bugs
Date: 09/07/2004 20:43:12
>Number:         26878
>Category:       kern
>Synopsis:       FFSv2 + softdep = livelock (no free ram)
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Sep 07 23:33:00 UTC 2004
>Originator:     Richard Earnshaw
>Release:        NetBSD 2.0_BETA
System: NetBSD 2.0_BETA NetBSD 2.0_BETA (OSPREY) #0: Thu Aug 5 20:31:21 BST 2004 cats
	Physical RAM 128M.  HDD: 80G Maxtor running in UDMA-1 mode.
Architecture: arm
Machine: cats
	creating a FFSv2 filesystem and then mounting it with soft 
	dependencies can lead to the situation where the kernel runs out of
	free memory if there is heavy disk activity (eg untarring a large
	amount of data).  The system isn't truly dead (top continues to
	run), but shows that there is only ~4k (1 page) of memory on the
	free list.  However, no new processes can be started and it's 
	impossible to kill any existing ones.
	As above.
	No idea.  Probably should ignore softdep flag if FFSv2 mode for now.