Messages in this thread | | | Date | Mon, 26 Jan 2015 10:02:55 +0100 | From | Jiri Olsa <> | Subject | Re: [PATCH 2/5] tools lib api fs: Add tracefs mount helper functions |
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On Sun, Jan 25, 2015 at 02:26:45PM -0500, Steven Rostedt wrote: > On Sun, 25 Jan 2015 17:56:19 +0100 > Jiri Olsa <jolsa@redhat.com> wrote: > > > On Sat, Jan 24, 2015 at 01:13:32PM -0500, Steven Rostedt wrote: > > > > SNIP > > > > > @@ -0,0 +1,29 @@ > > > +#ifndef __API_TRACEFS_H__ > > > +#define __API_TRACEFS_H__ > > > + > > > +#define _STR(x) #x > > > +#define STR(x) _STR(x) > > > + > > > +/* > > > + * On most systems <limits.h> would have given us this, but not on some systems > > > + * (e.g. GNU/Hurd). > > > + */ > > > +#ifndef PATH_MAX > > > +#define PATH_MAX 4096 > > > +#endif > > > + > > > +#ifndef TRACEFS_MAGIC > > > +#define TRACEFS_MAGIC 0x74726163 > > > +#endif > > > > I missed the point when tracefs became actual standalone > > filesystem.. I'll check ;-) > > > > Is it mutualy exclusive to 'debugfs/tracing' or those 2 can live together? > > > > I'm working on the patches right now. But when it happens perf should > be aware of it. I already updated trace-cmd to be aware. > > When tracefs is added, debugfs/tracing will automatically mount tracefs > when debugfs is mounted. As debugfs currently has some issues with > automounting, this part is being discussed currently as well. > > Note, WTF is perf checking the magic number for debugfs?? If events > move, even if its at the same path, this will break perf!
good question.. it's there since 2009: f6bdafef2ab9 perf_counter: Add tracepoint support to perf list, perf stat
I guess we didn't want anyone to trick us with fake tracepoints ;-)
jirka
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