Re: [Qemu-devel] [RFC v2 11/11] tcg: enable thread-per-vCPU

[Paolo Bonzini]

On 27/05/2016 17:07, Sergey Fedorov wrote:
>>> >>  1. Make 'cpu->thread_kicked' access atomic
>>> >>  2. Remove global 'exit_request' and use per-CPU 'exit_request'
>>> >>  3. Change how 'current_cpu' is set
>>> >>  4. Reorganize round-robin CPU TCG thread function
>>> >>  5. Enable 'mmap_lock' for system mode emulation (do we really want 
>>> >> this?)
>> > No, I don't think so.
>> >
>>> >>  6. Enable 'tb_lock' for system mode emulation
>>> >>  7. Introduce per-CPU TCG thread function
>> > At least 2/3/7 must be done at the same time, but I agree that this
>> > patch could use some splitting. :)
> Hmm, 2/3 do also change single-threaded CPU loop. I think they should
> apply separately from 7.

Reviewed the patch now, and I'm not sure how you can do 2/3 for the
single-threaded CPU loop.  They could be moved out of cpu_exec and into
cpus.c (in a separate patch), but you need exit_request and
tcg_current_cpu to properly kick the single-threaded CPU loop out of
qemu_tcg_cpu_thread_fn.

Thanks,

Paolo