Re: [RFC][PATCH 0/3] configfs: Make nested default groupslockdep-friendly

From: Joel Becker
Date: Tue May 20 2008 - 18:29:08 EST

On Tue, May 20, 2008 at 03:13:41PM -0700, Arjan van de Ven wrote:
> > Louis, what about sticking the recursion level on
> > configfs_dirent? That is, you could add sd->s_level and then use it
> > when needed. THis would hopefully avoid having to pass the level as
> > an argument to every function. Then we can go back to your original
> > scheme. If they recurse too much and hit the lockdep limit, just
> > rewind everything and return -ELOOP.
> you can also make a new lockdep key for each level... not pretty but it
> works

I think that's what we're talking about here. The toplevel is
I_MUTEX_PARENT, then each child has a class of (I_MUTEX_CHILD + depth),
where depth is the value of s_level. His original try passed depth
everywhere. I'm asking him to attach it to the configfs_dirent so that
the code stays readable. We run into a depth limit at
(MAX_LOCKDEP_SUBCLASS - I_MUTEX_PARENT - 1 == 5), which I think is
probably sane.
Do you mean something else? Perhaps not starting from



"Copy from one, it's plagiarism; copy from two, it's research."
- Wilson Mizner

Joel Becker
Principal Software Developer
E-mail: joel.becker@xxxxxxxxxx
Phone: (650) 506-8127
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at