[v12] ref_tracker: add ability to register a debugfs file for a ref_tracker_dir

[PATCH v12 03/10] ref_tracker: add a top level debugfs directory for ref_tracker

Posted by Jeff Layton 8 months, 2 weeks ago

Add a new "ref_tracker" directory in debugfs. Each individual refcount
tracker can register files under there to display info about
currently-held references.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 lib/ref_tracker.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/lib/ref_tracker.c b/lib/ref_tracker.c
index de71439e12a3bab6456910986fa611dfbdd97980..d374e5273e1497cac0d70c02c282baa2c3ab63fe 100644
--- a/lib/ref_tracker.c
+++ b/lib/ref_tracker.c
@@ -273,3 +273,16 @@ int ref_tracker_free(struct ref_tracker_dir *dir,
 	return 0;
 }
 EXPORT_SYMBOL_GPL(ref_tracker_free);
+
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+
+static struct dentry *ref_tracker_debug_dir = (struct dentry *)-ENOENT;
+
+static int __init ref_tracker_debugfs_init(void)
+{
+	ref_tracker_debug_dir = debugfs_create_dir("ref_tracker", NULL);
+	return 0;
+}
+late_initcall(ref_tracker_debugfs_init);
+#endif /* CONFIG_DEBUG_FS */

-- 
2.49.0

Re: [PATCH v12 03/10] ref_tracker: add a top level debugfs directory for ref_tracker

Posted by Jani Nikula 8 months, 1 week ago

On Thu, 29 May 2025, Jeff Layton <jlayton@kernel.org> wrote:
> Add a new "ref_tracker" directory in debugfs. Each individual refcount
> tracker can register files under there to display info about
> currently-held references.
>
> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
>  lib/ref_tracker.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
>
> diff --git a/lib/ref_tracker.c b/lib/ref_tracker.c
> index de71439e12a3bab6456910986fa611dfbdd97980..d374e5273e1497cac0d70c02c282baa2c3ab63fe 100644
> --- a/lib/ref_tracker.c
> +++ b/lib/ref_tracker.c
> @@ -273,3 +273,16 @@ int ref_tracker_free(struct ref_tracker_dir *dir,
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(ref_tracker_free);
> +
> +#ifdef CONFIG_DEBUG_FS
> +#include <linux/debugfs.h>
> +
> +static struct dentry *ref_tracker_debug_dir = (struct dentry *)-ENOENT;

Nitpick, please prefer ERR_PTR(-ENOENT) over casting inline.

BR,
Jani.


> +
> +static int __init ref_tracker_debugfs_init(void)
> +{
> +	ref_tracker_debug_dir = debugfs_create_dir("ref_tracker", NULL);
> +	return 0;
> +}
> +late_initcall(ref_tracker_debugfs_init);
> +#endif /* CONFIG_DEBUG_FS */

-- 
Jani Nikula, Intel

Re: [PATCH v12 03/10] ref_tracker: add a top level debugfs directory for ref_tracker

Posted by Jeff Layton 8 months ago

On Wed, 2025-06-04 at 12:12 +0300, Jani Nikula wrote:
> On Thu, 29 May 2025, Jeff Layton <jlayton@kernel.org> wrote:
> > Add a new "ref_tracker" directory in debugfs. Each individual refcount
> > tracker can register files under there to display info about
> > currently-held references.
> > 
> > Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> > Signed-off-by: Jeff Layton <jlayton@kernel.org>
> > ---
> >  lib/ref_tracker.c | 13 +++++++++++++
> >  1 file changed, 13 insertions(+)
> > 
> > diff --git a/lib/ref_tracker.c b/lib/ref_tracker.c
> > index de71439e12a3bab6456910986fa611dfbdd97980..d374e5273e1497cac0d70c02c282baa2c3ab63fe 100644
> > --- a/lib/ref_tracker.c
> > +++ b/lib/ref_tracker.c
> > @@ -273,3 +273,16 @@ int ref_tracker_free(struct ref_tracker_dir *dir,
> >  	return 0;
> >  }
> >  EXPORT_SYMBOL_GPL(ref_tracker_free);
> > +
> > +#ifdef CONFIG_DEBUG_FS
> > +#include <linux/debugfs.h>
> > +
> > +static struct dentry *ref_tracker_debug_dir = (struct dentry *)-ENOENT;
> 
> Nitpick, please prefer ERR_PTR(-ENOENT) over casting inline.
> 
> 
Sorry I didn't respond to this earlier. I'd prefer that too, but when I
try that, I get:

lib/ref_tracker.c:327:47: error: initializer element is not constant
  327 | static struct dentry *ref_tracker_debug_dir = ERR_PTR(-ENOENT);
      |                                               ^~~~~~~


> 
> > +
> > +static int __init ref_tracker_debugfs_init(void)
> > +{
> > +	ref_tracker_debug_dir = debugfs_create_dir("ref_tracker", NULL);
> > +	return 0;
> > +}
> > +late_initcall(ref_tracker_debugfs_init);
> > +#endif /* CONFIG_DEBUG_FS */

-- 
Jeff Layton <jlayton@kernel.org>

Re: [PATCH v12 03/10] ref_tracker: add a top level debugfs directory for ref_tracker

Posted by Krzysztof Karas 8 months, 2 weeks ago

Hi Jeff,

> Add a new "ref_tracker" directory in debugfs. Each individual refcount
> tracker can register files under there to display info about
> currently-held references.
> 
> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---

Reviewed-by: Krzysztof Karas <krzysztof.karas@intel.com>

Best Regards,
Krzysztof