Re: [FIXED?] More on the blkfree panic

On  3 May, Joe Marcus Clarke wrote:
> On Sat, 2003-05-03 at 05:42, Don Lewis wrote:

>> Interesting ... I'm having problems reproducing this problem.
>> 
>> The first report of this bug landed in my inbox at about 15:12 UTC on
>> April 27.  Someone else who reported the bug claimed to have cvsup'ed at
>> about 10:00 UTC on that day.
>> 
>> I just did
>> 	cvs -R update -Pd -D'4/27/2003 14:00:00 UTC'
>> 	make buildworld
>> 	make buildkernel
>> 	make installkernel
>> and rebooted.
>> 
>> I haven't managed to trigger the problem with a simultaneous buildworld
>> and untaring ports.tgz.  I even suspected that this problem might be
>> triggered by free memory pressure so I added
>> 	hw.physmem="128M"
>> to /boot/loader.conf and rebooted.  I've pushed the machine heavily into
>> paging, but it still seems to be stable, but painfully sluggish.
> 
> I was also able to reproduce this, though not as reliably as my
> localhost NFS mount trick, by doing a make extract in
> x11/XFree86-4-libraries.  This was on a lightly loaded P4 with 1 GB of
> RAM and UFS1 file systems.

I tried running this in a loop for a while, but still no sign of a
problem.  The system is an Athlon XP with 1 GB of RAM, a single UFS1
file system on a 10K RPM Seagate Cheetah SCSI drive with write-caching
disabled.

I can't try the NFS mount trick unless I rebuild the kernel to disable
the DEBUG_VFS_LOCKS option.  With this option enabled the NFS server
code fails the vnode lock assertions very quickly.

BTW, that puppy makes some very interesting humming sounds when the
memory is cranked down and it is paging heavily, at around 240 I/O's per
second ;-)


On  3 May, Joe Marcus Clarke wrote:

> Just as an update.  After Alan's recent VM commits, the problem seems to
> be resolved.  I have been running my localhost NFS tinderbox build for a
> while, and the machine has not rebooted...yet.

Yeah, that vfs_subr.c commit sure looks suspicious.  Maybe I've just
been lucky not to have run into this problem since I've been running
with the bad version of this file all along.