Re: [Qemu-devel] SMP and qemu scheduler, HELP

[Peter Maydell]

On 25 August 2015 at 10:29, françois Guerret
<address@hidden> wrote:
> I want to execute a realtime software which executes periodically the same
> loop.
> On multicore target, I set one periodic loop per core.
>
> I need the time to be synchronized between the cores at least with the
> granularity of a loop period.
> For instance I want to prevent core 0 to execute three time its loop while
> core 1 executes its own once.
>
> Moreover I want to use *time* (icount time) to synchornize the loops (hence
> a barrier using an active waiting
> is definitly not a good solution). Indeed I need the icount time necessary
> to execute the loop to be more or less constant.

I think it is unlikely that QEMU will ever provide emulation
with that degree of fidelity and lock-step between different
emulated CPUs. You would be better to make sure your code
doesn't rely on such fine detail of timing synchronization
between the code executed on different cores.

thanks
-- PMM