Re: [PATCH 5/5] perf: Make perf aware of tracefs

[Jiri Olsa <jolsa@redhat.com>]

On Sat, Jan 24, 2015 at 01:13:35PM -0500, Steven Rostedt wrote:

SNIP

> @@ -351,11 +385,15 @@ const char *find_tracing_dir(void)
>  	if (tracing_found)
>  		return tracing;
>  
> -	debugfs = find_debugfs();
> -	if (!debugfs)
> -		return NULL;
> +	debugfs = find_tracefs();
> +	if (!debugfs) {
> +		tracing_dir = "/tracing";
> +		debugfs = find_debugfs();
> +		if (!debugfs)
> +			return NULL;

so this pattern 'try tracefs, if that does not work try debugfs'
is all over the patch.. how about we add new new 'virtual' fs to
encapsulate that, like:

  with followign interface:
    bool tpfs_configured(void);
    const char *tpfs_find_mountpoint(void);
    int tpfs_valid_mountpoint(const char *debugfs);
    char *tpfs_mount(const char *mountpoint);
    extern char tpfs_mountpoint[];

It does not neceserily needs to reside in tools/lib/api/fs/tpfs.[ch],
but I believe we need some form of encapsulation for this.

jirka