Re: [Qemu-devel] [PATCH v2 07/29] trace: Do not include qom/cpu.h into generated trace.h

[Stefan Hajnoczi]

On Tue, Aug 06, 2019 at 05:14:13PM +0200, Markus Armbruster wrote:
> docs/devel/tracing.txt explains "since many source files include
> trace.h, [the generated trace.h use] a minimum of types and other
> header files included to keep the namespace clean and compile times
> and dependencies down."
> 
> Commit 4815185902 "trace: Add per-vCPU tracing states for events with
> the 'vcpu' property" made them all include qom/cpu.h via
> control-internal.h.  qom/cpu.h in turn includes about thirty headers.
> Ouch.
> 
> Per-vCPU tracing is currently not supported in sub-directories'
> trace-events.  In other words, qom/cpu.h can only be used in
> trace-root.h, not in any trace.h.
> 
> Split trace/control-vcpu.h off trace/control.h and
> trace/control-internal.h.  Have the generated trace.h include
> trace/control.h (which no longer includes qom/cpu.h), and trace-root.h
> include trace/control-vcpu.h (which includes it).
> 
> The resulting improvement is a bit disappointing: in my "build
> everything" tree, some 1100 out of 6600 objects (not counting tests
> and objects that don't depend on qemu/osdep.h) depend on a trace.h,
> and about 600 of them no longer depend on qom/cpu.h.  But more than
> 1300 others depend on trace-root.h.  More work is clearly needed.
> Left for another day.
> 
> Cc: Stefan Hajnoczi <address@hidden>
> Signed-off-by: Markus Armbruster <address@hidden>
> ---
>  block/block-backend.c         |  1 +
>  qom/object.c                  |  1 +
>  scripts/tracetool/format/c.py |  1 +
>  scripts/tracetool/format/h.py |  7 +++-
>  trace/control-internal.h      | 25 --------------
>  trace/control-vcpu.h          | 63 +++++++++++++++++++++++++++++++++++
>  trace/control.h               | 24 -------------
>  trace/qmp.c                   |  2 +-
>  ui/vnc.c                      |  1 +
>  9 files changed, 74 insertions(+), 51 deletions(-)
>  create mode 100644 trace/control-vcpu.h

Reviewed-by: Stefan Hajnoczi <address@hidden>