Swapfile problem in 6?

[Brian Fundakowski Feldman]

On Tue, Nov 15, 2005 at 09:49:57PM +0100, Lars Kristiansen wrote:
> > On Tue, Nov 15, 2005 at 02:15:37AM -0800, Rob wrote:
> >>
> >> One more thing, for those who are reading this thread.
> >>
> >> Concerning my kernel locking up while using a
> >> swapfile:
> >>
> >> I had an infinite while loop running during the
> >> kernel compilation, printing out 'swapinfo' every
> >> 15 seconds. The last output before the machine goes
> >> dead is this:
> >>
> >>  /dev/ad0s1b         39848    11820    39848    30%
> >>  /dev/md0           131072     5908   131072     5%
> >>  Total              170920    17728   153192    10%
> >>
> >> which means that swap space is OK right before the
> >> freeze, but within 15 seconds from here, the kernel
> >> locks up....
> >
> > In my experience, fifteen seconds is enough to fill up 130+MB of swap,
> > so a much smaller polling interval is necessary.
> 
> Probably true, but when trying with only one swap partition instead of
> swapfile, and that partition gets filled up, the build process failed and
> the computer continued to work as normal.

Yeah, it sounds like you're running into a buffer cache/VFS/VM deadlock.
They're nasty, but generally not hard to fix individually.

-- 
Brian Fundakowski Feldman                           \'[ FreeBSD ]''''''''''\
  <> green at FreeBSD.org                               \  The Power to Serve! \
 Opinions expressed are my own.                       \,,,,,,,,,,,,,,,,,,,,,,\