Re: [PATCH v2 5/6] tracing: Introduce remove_event_file_dir()

[Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>]

(2013/07/27 2:25), Oleg Nesterov wrote:
> Preparation for the next patch. Extract the common code from
> remove_event_from_tracers() and __trace_remove_event_dirs()
> into the new helper, remove_event_file_dir().
> 
> The patch looks more complicated than it actually is, it also
> moves remove_subsystem() up to avoid the forward declaration.

Looks good for me.

Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>

Thanks!

> 
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
> ---
>  kernel/trace/trace_events.c |   47 +++++++++++++++++++++----------------------
>  1 files changed, 23 insertions(+), 24 deletions(-)
> 
> diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
> index 3de2aca..2a4f68a 100644
> --- a/kernel/trace/trace_events.c
> +++ b/kernel/trace/trace_events.c
> @@ -409,11 +409,31 @@ static void put_system(struct ftrace_subsystem_dir *dir)
>  	mutex_unlock(&event_mutex);
>  }
>  
> +static void remove_subsystem(struct ftrace_subsystem_dir *dir)
> +{
> +	if (!dir)
> +		return;
> +
> +	if (!--dir->nr_events) {
> +		debugfs_remove_recursive(dir->entry);
> +		list_del(&dir->list);
> +		__put_system_dir(dir);
> +	}
> +}
> +
>  static void *event_file_data(struct file *filp)
>  {
>  	return ACCESS_ONCE(file_inode(filp)->i_private);
>  }
>  
> +static void remove_event_file_dir(struct ftrace_event_file *file)
> +{
> +	list_del(&file->list);
> +	debugfs_remove_recursive(file->dir);
> +	remove_subsystem(file->system);
> +	kmem_cache_free(file_cachep, file);
> +}
> +
>  /*
>   * Open and update trace_array ref count.
>   * Must have the current trace_array passed to it.
> @@ -1545,33 +1565,16 @@ event_create_dir(struct dentry *parent,
>  	return 0;
>  }
>  
> -static void remove_subsystem(struct ftrace_subsystem_dir *dir)
> -{
> -	if (!dir)
> -		return;
> -
> -	if (!--dir->nr_events) {
> -		debugfs_remove_recursive(dir->entry);
> -		list_del(&dir->list);
> -		__put_system_dir(dir);
> -	}
> -}
> -
>  static void remove_event_from_tracers(struct ftrace_event_call *call)
>  {
>  	struct ftrace_event_file *file;
>  	struct trace_array *tr;
>  
>  	do_for_each_event_file_safe(tr, file) {
> -
>  		if (file->event_call != call)
>  			continue;
>  
> -		list_del(&file->list);
> -		debugfs_remove_recursive(file->dir);
> -		remove_subsystem(file->system);
> -		kmem_cache_free(file_cachep, file);
> -
> +		remove_event_file_dir(file);
>  		/*
>  		 * The do_for_each_event_file_safe() is
>  		 * a double loop. After finding the call for this
> @@ -2301,12 +2304,8 @@ __trace_remove_event_dirs(struct trace_array *tr)
>  {
>  	struct ftrace_event_file *file, *next;
>  
> -	list_for_each_entry_safe(file, next, &tr->events, list) {
> -		list_del(&file->list);
> -		debugfs_remove_recursive(file->dir);
> -		remove_subsystem(file->system);
> -		kmem_cache_free(file_cachep, file);
> -	}
> +	list_for_each_entry_safe(file, next, &tr->events, list)
> +		remove_event_file_dir(file);
>  }
>  
>  static void
> 


-- 
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com