Re: [Qemu-devel] [PATCH for-2.8 v1 10/60] trace: remove fixed global event state arrays

["Daniel P. Berrange" <berrange@redhat.com>]

On Wed, Aug 10, 2016 at 04:00:17PM +0200, Lluís Vilanova wrote:
> Daniel P Berrange writes:
> [...]
> > diff --git a/scripts/tracetool/format/events_c.py b/scripts/tracetool/format/events_c.py
> > index 9203377..bab6404 100644
> > --- a/scripts/tracetool/format/events_c.py
> > +++ b/scripts/tracetool/format/events_c.py
> > @@ -25,7 +25,10 @@ def generate(events, backend):
> >          '#include "trace/control.h"',
> >          '')
>  
> > -    out('TraceEvent trace_events[TRACE_EVENT_COUNT] = {')
> > +    out('uint16_t dstate[TRACE_EVENT_COUNT];')
> > +    out('bool dstate_init[TRACE_EVENT_COUNT];')
> > +
> > +    out('static TraceEvent trace_events[TRACE_EVENT_COUNT] = {')
>  
> >      for e in events:
> >          if "vcpu" in e.properties:
> 
> I'd rather keep them as 'trace_events_dstate' and 'trace_events_dstate_init' if
> most references are auto-generated. Or maybe I just missed something.

Later patches rename this again, giving it a custom prefix for each
group

> Also, maybe we should just try to get rid of the dstate_init structure. Only
> vcpu events need late initialization, which could be something like:
> 
>    trace_events_enabled_count--;
>    dstate[ev->id]--;
>    trace_event_set_state_dynamic(dstate, ev, true);
> 
> Non-vcpu events shouldn't need late initialization.

I'd rather not try to refactor that logic at the same time - it could
be done as a later patch, or if you want to submit a patch to fix that
I can rebase on top of it.

> [...]
> > diff --git a/stubs/trace-control.c b/stubs/trace-control.c
> > index fe59836..31566c2 100644
> > --- a/stubs/trace-control.c
> > +++ b/stubs/trace-control.c
> > @@ -11,16 +11,12 @@
> >  #include "trace/control.h"
>  
>  
> > -void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
> > +void trace_event_set_state_dynamic(uint16_t *dstate, TraceEvent *ev, bool state)
> >  {
> > -    TraceEventID id;
> >      assert(trace_event_get_state_static(ev));
> > -    id = trace_event_get_id(ev);
> > -    trace_events_enabled_count += state - trace_events_dstate[id];
> > -    trace_events_dstate[id] = state;
> >  }
> 
> Should not be empty (here, stub means it's not target code).

Oh hmm, for qemu-img & friends, i geuss

Regards,
Daniel
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