Re: XFS Lock debugging noise or real problem?

[Linda Walsh <xfs@tlinx.org>]

Dave Chinner wrote:
> I've asked the lockdep ppl to treat stuff like memory reclaim and
> the iprune_mutex specially because of this recursive calling nature
> of memory reclaim, but so far nothing has happened....
---
	So it's really a kernel bug, not an XFS bug...(?)


> FWIW, I think that recent changes have resulted in the xfs_fsr case
> (swap_extents) being annotated properly so that one should go
> away.
---
	If it was limited to xfs_fsr, that'd be tolerable -- but its
cropping up in random user-level-apps (imaps, sort, et al).



> Well, any debugging code is really designed for test and dev systems,
> not for production systems.....
---
	The lock-correctness code is described as a feature to provide
"provability".  It's not called "debugging" and I don't regard that as
"debugging" -- but something that any production system that wants
operational integrity over a minor 'speed hit', would "theoretically"
want.

	If it is "debug" code, it should be labeled as such -- but
code that can mathematically guarantee that parts of the kernel operate
correctly seems like a _reliability_ feature, not a debugging feature.

	Thanks for the insight -- very appreciated.

linda