[ltt-dev] [RFC PATCHv2 4/5] urcu: re-implment urcu-qsbr

[Paolo Bonzini]

On 08/25/2011 08:03 AM, Lai Jiangshan wrote:
>
> My synchronize_rcu() is slower. (will be optimized)
> At the sametime, I test Paolo's patch, I don't know why it slowdowns synchronize_rcu()
> in my box.

I think you can try changing the number of busy wait cycles before it 
starts using the futex.  I was measuring with 10 readers, not 3.  It 
makes sense to wait more with fewer readers.

Paolo