Re: adding trace-cmd's plugins to perf

[Arnaldo Carvalho de Melo <acme@ghostprotocols.net>]

Em Tue, Apr 12, 2011 at 06:22:47PM +0200, Frederic Weisbecker escreveu:
> On Sat, Apr 09, 2011 at 09:50:29PM -0600, David Ahern wrote:
> > Right now perf script cannot process kvm tracepoints:
> > 
> > perf record -e kvm:* -p 6446 -- sleep 5
> > 
> > perf script
> >   Warning: Error: expected type 4 but read 7

> > are about merging common code between the two commands. Also, trace-cmd and perf
> > are in separate repositories so a shared lib is going to inconvenience
> > one of the two.
> 
> So, we copied the tools/perf/util/trace-event-* files from trace-cmd to perf
> a while go. Then both files took their own path, both pulling fixes/enhancement
> from each others (probably more in the trace-cmd -> perf direction).
> 
> And perf is indeed a bit backward wrt parsing, because it lacks those plugins
> for example. So now it would be nice to unify that in a common lib so that it
> works well in both.
> 
> Steve proposed a shared tools/trace.so, that perf and trace-cmd could plug
> into, I really would like to see that happening too.
> 
> I think Ingo had some reserves about this, due to potential versioning
> and compatibility that such a dynamic lib would involve.

So we don't commit to an ABI for a while, just linking with it, changing
users when changing the ABI.

I encourage David to go and add the bits of trace-cmd he needs for
support the plugins he wants used in perf on tools/lib/ and make perf
use it.

That way we again reduce the differences between the codebases, or at least
reduce the feature gap.

- Arnaldo