Re: Oops in prune_dcache (2.4.0-prerelease)

[Linus Torvalds]

On Wed, 3 Jan 2001, Udo A. Steinberg wrote:
> 
> While under massive disk and cpu load, 2.4.0-prerelease produced
> the following oops (decode see below)

Hmm.. If I'm not mistaken, this is in dentry_iput() (inline function
called by prune_one_dentry(), which is _also_ an inline function, which
is why it gets reported as being in prune_dcache):

	if (dentry->d_op && dentry->d_op->d_iput)
		dentry->d_op->d_iput(dentry, inode);

and it looks like your dentry->d_op has a value of 0x01000000, so when we
load the d_op->d_iput pointer, we get a page fault.

The strange thing is that 0x01000000 value, which almost certainly should
just be NULL. A one-bit error.

Now, I assume this machine has been historically stable, with no history
of memory corruption problems.. It's entirely possible (and likely) that
the one-bit error is due to some wild kernel pointer. Which makes this
_really_ hard to debug.

I'll try to think about it some more, but I'd love to have more reports to
go on to try to find a pattern..

		Linus