Lockdep is less useful than it was

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, Dec 07, 2017 at 11:06:34AM -0500, Theodore Ts'o wrote:
> The problem is that if it has too many false positives --- and it's
> gotten *way* worse with the completion callback "feature", people will
> just stop using Lockdep as being too annyoing and a waste of developer
> time when trying to figure what is a legitimate locking bug versus
> lockdep getting confused.
> 
> <Rant>I can't even disable the new Lockdep feature which is throwing
> lots of new false positives --- it's just all or nothing.</Rant>

You *can* ... but it's way more hacking Kconfig than you ought to have
to do (which is a separate rant ...)

You need to get LOCKDEP_CROSSRELEASE off.  I'd revert patches
e26f34a407aec9c65bce2bc0c838fabe4f051fc6 and
b483cf3bc249d7af706390efa63d6671e80d1c09

I think it was a mistake to force these on for everybody; they have a
much higher false-positive rate than the rest of lockdep, so as you say
forcing them on leads to fewer people using *any* of lockdep.

The bug you're hitting isn't Byungchul's fault; it's an annotation
problem.  The same kind of annotation problem that we used to have with
dozens of other places in the kernel which are now fixed.  If you didn't
have to hack Kconfig to get rid of this problem, you'd be happier, right?
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux