Messages in this thread | | | Date | Fri, 13 Apr 2012 23:25:28 +0900 | From | Takuya Yoshikawa <> | Subject | Re: [PATCH 00/13] KVM: MMU: fast page fault |
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Xiao,
Takuya Yoshikawa <takuya.yoshikawa@gmail.com> wrote:
> > What is your really want to say but i missed? > > How to improve and what we should pay for that. > > Note that I am not objecting to O(1) itself. >
I forgot to say one important thing -- I might give you wrong impression.
I am perfectly fine with your lock-less work. It is really nice!
The reason I say much about O(1) is that O(1) and rmap based GET_DIRTY_LOG have fundamentally different characteristics.
I am thinking really seriously how to make dirty page tracking work well with QEMU in the future.
For example, I am thinking about multi-threaded and fine-grained GET_DIRTY_LOG.
If we use rmap based GET_DIRTY_LOG, we can restrict write protection to only a selected area of one guest memory slot.
So we may be able to make each thread process dirty pages independently from other threads by calling GET_DIRTY_LOG for its own area.
But I know that O(1) has its own good point. So please wait a bit. I will write up what I am thinking or send patches.
Anyway, I am looking forward to your lock-less work! It will improve the current GET_DIRTY_LOG performance.
Thanks, Takuya
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