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Subject: Re: [RFC PATCHSET] sched,perf: unify tracers in sched and move
 perf on top of TP
From: Peter Zijlstra <peterz@infradead.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: Tejun Heo <tj@kernel.org>, efault@gmx.de, avi@redhat.com, paulus@samba.org,
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Date: Wed, 05 May 2010 20:12:53 +0200
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On Wed, 2010-05-05 at 18:55 +0200, Ingo Molnar wrote:
> * Tejun Heo <tj@kernel.org> wrote:
> 
> > Hello,
> > 
> > On 05/05/2010 01:38 PM, Peter Zijlstra wrote:
> > > As it stands I'd argue to simply drop this whole idea. The SCHED_EVENT()
> > > thing doesn't look like its worth the obfuscation and I'm very much
> > > opposed to making perf and sched_notifiers rely on tracepoints.
> > 
> > Hmmm... okay.  Well, this thing is born out of Ingo's suggestion that for 
> > more sched notifiers to be added notification mechanisms need to be 
> > consolidated.  As long as I can get those two notifiers needed for cmwq, 
> > it's okay with me.  Ingo, what do you think?
> 
> I'd much rather see the *_EVENT() APIs used - but enhanced to address Peter's 
> objections. One change would be to add a DEFINE_EVENT_ABI() variant, which 
> would be called via trace_abi_*() calls. That way we always know they are 
> 'hardwired' events in the extreme.
> 
> That then would allow the software events to be consolidated.
> 
> Peter?

Well, I'd much rather just see a direct call in the code than having to
reverse engineer wth hangs onto that _EVENT() junk.

Also, we don't need ABI muck for this.