On Mon, Mar 31, 2014 at 7:37 PM, Andreas Färber <afaer...@suse.de> wrote: > CPU address spaces touching load and store helpers as well as the > movement of (almost) all fields from CPU_COMMON to CPUState have led to > a noticeable increase of CPU() usage in "hot" paths for both TCG and KVM. > > While CPU()'s OBJECT_CHECK() might help detect development errors, i.e. > in form of crashes due to QOM vs. non-QOM mismatches rather than QOM > type mismatches, it is not really needed at runtime since mostly used in > CPU-specific paths, coming from a target-specific CPU subtype. If that > pointer is damaged, other errors are highly likely to occur elsewhere > anyway. > > Keep the CPU() macro for a consistent developer experience and for > flexibility to exchange its implementation, but turn it into a pure, > unchecked C cast for now. > > Compare commit 6e42be7cd10260fd3a006d94f6c870692bf7a2c0. > > Reported-by: Laurent Desnogues <laurent.desnog...@gmail.com> > Suggested-by: Paolo Bonzini <pbonz...@redhat.com> > Signed-off-by: Andreas Färber <afaer...@suse.de>
It works fine here. Tested-by: Laurent Desnogues <laurent.desnog...@gmail.com> Thanks, Laurent > --- > include/qom/cpu.h | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/include/qom/cpu.h b/include/qom/cpu.h > index f99885a..df977c8 100644 > --- a/include/qom/cpu.h > +++ b/include/qom/cpu.h > @@ -53,7 +53,12 @@ typedef uint64_t vaddr; > > #define TYPE_CPU "cpu" > > -#define CPU(obj) OBJECT_CHECK(CPUState, (obj), TYPE_CPU) > +/* Since this macro is used a lot in hot code paths and in conjunction with > + * FooCPU *foo_env_get_cpu(), we deviate from usual QOM practice by using > + * an unchecked cast. > + */ > +#define CPU(obj) ((CPUState *)(obj)) > + > #define CPU_CLASS(class) OBJECT_CLASS_CHECK(CPUClass, (class), TYPE_CPU) > #define CPU_GET_CLASS(obj) OBJECT_GET_CLASS(CPUClass, (obj), TYPE_CPU) > > -- > 1.8.4.5 > >
