Disabling CONFIG_QOM_CAST_DEBUG in Fedora qemu builds

[Richard W.M. Jones]

On Fri, Oct 06, 2023 at 11:02:27PM +0200, Paolo Bonzini wrote:
> 
> 
> Il ven 6 ott 2023, 20:36 Richard W.M. Jones <rjones at redhat.com> ha scritto:
> 
>     I patched my copy of qemu to add ../configure --disable-qom-cast-debug
>     flag.  This reduced the time taken to run two test compiles inside the
>     guest from [465, 467] seconds down to [445, 441] seconds, which is a
>     saving of about 5%.
> 
>     Or ... maybe someone knows a way to disable the debugging code when
>     called from particular call sites?
> 
> 
> You can replace the hottest sites with just a C cast. The only one I see in the
> flame graph is cpu_get_tb_cpu_state().

You're right - I'll CC you on a patch I'll send to the qemu-devel
lists soon.

Rich.

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