Re: [PATCH 0/8] [GIT PULL] TRACE_EVENT for modules

[Theodore Tso <tytso@mit.edu>]

On Tue, Apr 14, 2009 at 01:23:37PM -0400, Steven Rostedt wrote:
> 
> Removal of the two headers per trace system. No need to have
> include/trace/sched.h and include/linux/sched_event_types.h
> All the changes go into include/trace/sched.h. But note that how that
> file is made is important. One could look at the sched.h file, or
> skb.h, lockdep.h and kmem.h as an example.

Hi Steven,

One thing which I would really like is to avoid needing to drop the
header file in include/trace/<subsystem.h>.

The problem that I have with this is that for ext4, we need to access
private data structures which are defined in header files in
fs/ext4/*.h --- which we moved into fs/ext4 a long time ago at the
request of those who felt include/linux/* was getting rather
cluttered, and if a subsystem had header files which were only needed
by files for that particular subsystems, they should be moved out of
include/linux.  

I supported the above-mentioned cleanup, but it's causing problems
given that include/trace/ext4_events_types.h (or include/trace/ext4.h
in the new world order) needs access to various structure definitions
in fs/ext4/*.h.  I could move the required header files into
include/linux/ext4_tracing_types.h --- which has the downside that it
is a very random collection of data structures --- or I could entirely
revert the cleanup we did long ago and move all of the ext4 header
files back into include/linux.  But better yet would be if there was
some way we could tell the tracing subsystem that tracing header file
for ext4 could be found in fs/ext4/ext4_trace.h.

Any chance you could support something like this?

Thanks, regards,

    	       	     	     	       	  - Ted