Re: "0-order allocation failed"

[tls@reefedge.com]

On Sun, Aug 19, 2001 at 07:59:39PM +0200, Seth Mos wrote:
> 
> The error message is a general kernel error message which seems to be a 
> highmem problem.

I don't see it unless I use XFS.  I don't see it, on this exact same
system, with ext2 or reiserfs.

> >I see mention of this bug in a list message from April, but nothing since
> >then.  Has it been fixed, or even analyzed?  If it's been fixed, is there a
> >simple patch against 1.0.1 or will I need to run the latest from CVS?
> 
> I guess that using a kernel later then 2.4.5 may help but this is not 
> directly a XFS related error but XFS will help exposing this message 
> because it pushes the VM harder.

What does "pushes the VM harder" mean, in this context?

> I don't know if the highmem stuff is significantly better in 2.4.9.
> That is the current CVS tree version which is probably your best bet for 
> testing. A 2.4.8 patch is also available on the FTP site.

I noticed a later list message suggesting that a change to XFS in the 2.4.6
timeframe should significantly improve stability on highmem machines; I also
found a message suggesting that there were deadlocks elsewhere in the Linux
kernel on highmem machines until 2.4.7.  So I had high hopes for the 2.4.9
patch.

Unfortunately, though I haven't gotten the machine to hang hard yet, I'm
now running 2.4.9 and a simple cp -R of our CVS repository from one directory
on an XFS filesystem to another produces the "0 order alloc" messages.

Is this actually believed to be fixed at the moment, or not?  Looks like
not, but I'll leave this running for a few hours and see if I can get an
actual hang.

Thor