Re: [Intel-gfx] [PATCH v4 03/10] lib/ref_tracker: add printing to memory buffer

[Andi Shyti]

Hi Andrzej,

This looks also good, just few questions.

On Mon, Mar 06, 2023 at 05:31:59PM +0100, Andrzej Hajda wrote:
> In case one wants to show stats via debugfs.

shall I say it? I'll say it... you can do better with the log
here. It's not a typo fix :)

> Signed-off-by: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>

[...]

> +void __ref_tracker_dir_print(struct ref_tracker_dir *dir,
> +			   unsigned int display_limit)
> +{
> +	struct ostream os = {};
> +
> +	__ref_tracker_dir_pr_ostream(dir, display_limit, &os);
> +}
>  EXPORT_SYMBOL(__ref_tracker_dir_print);
>  
>  void ref_tracker_dir_print(struct ref_tracker_dir *dir,
> @@ -114,6 +141,19 @@ void ref_tracker_dir_print(struct ref_tracker_dir *dir,
>  }
>  EXPORT_SYMBOL(ref_tracker_dir_print);
>  
> +int ref_tracker_dir_snprint(struct ref_tracker_dir *dir, char *buf, size_t size)

nit: snprintf is normally referred to its variable parameter
counterpart... I would choose a different name... how about
ref_tracker_dir_fetch_print()?

> +{
> +	struct ostream os = { .buf = buf, .size = size };
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&dir->lock, flags);
> +	__ref_tracker_dir_pr_ostream(dir, 16, &os);
> +	spin_unlock_irqrestore(&dir->lock, flags);

What are you trying to protect with this spinlock? what if
the caller has already locked here? do we need a _locked()
version?

Thanks,
Andi

> +	return os.used;
> +}
> +EXPORT_SYMBOL(ref_tracker_dir_snprint);
> +
>  void ref_tracker_dir_exit(struct ref_tracker_dir *dir)
>  {
>  	struct ref_tracker *tracker, *n;
> 
> -- 
> 2.34.1