[dm-devel] [Bcache v14 16/16] bcache: Debug and tracing code

[Kent Overstreet]

On Tue, Jun 12, 2012 at 10:35:43AM -0700, Joe Perches wrote:
> "(uint64_t *)k - i->d" is what type again?
> What is a %zu?
> 
> Isn't that a mismatch?

You're right - ssize_t and size_t. I think gcc just isn't checking
signedness at all, that %i should be a %u too. Good catch.

> 
> > > > +static int debug_seq_show(struct seq_file *f, void *data)
> > > > +{
> > > > +	static const char *tabs = "\t\t\t\t\t";
> > > 
> > > Seems a _very_ odd use.
> > 
> > It is a strange hack.
> > 
> > The idea is that we want to indent more as we recurse; we could build up
> > a new string of tabs each time we recurse that's got one more tab than
> > our parent's, but that'd be a pain in the ass and it'd use more stack
> > space (though that should be fine here), so instead it's just
> > decrementing the pointer to the tab string to produce a string with one
> > more tab.
> 
> It's a nice idea, but that's not what's happening
> as I believe you reference tabs only once as &tabs[4]

bch_btree_dump() prints out tabs, and passes tabs - 1 when it recurses.