Re: [Qemu-devel] [PATCH 7/7] coroutine: try harder not to delete coroutines

[Peter Lieven]

Am 29.11.2014 um 15:27 schrieb Paolo Bonzini:
>
> On 28/11/2014 21:52, Peter Lieven wrote:
>> master:
>> Run operation 40000000 iterations 13.612604 s, 2938K operations/s, 340ns per 
>> coroutine
>>
>> this series up to patch 6:
>> Run operation 40000000 iterations 10.428382 s, 3835K operations/s, 260ns per 
>> coroutine
>>
>> this series up to patch 7:
>> Run operation 40000000 iterations 9.112539 s, 4389K operations/s, 227ns per 
>> coroutine
>>
>> So this confirms the +33% Paolo sees up to Patch 5. But I have yet fully 
>> understood the
>> +15% that this Patch gains.
> No atomic operations once the release pool gets full.  We're talking of
> 800 clock cycles here, and one atomic operation costs 50 cycles.  100
> clock cycles out of 800 = 15% speedup (8/7 = 1.14).

Maybe its worth mentioning this (partly) in the commit message that this can 
give a gain
of additional 15% best case. This gives a +50% for the whole series best case.

Peter