Messages in this thread | | | Subject | Re: [RFC PATCH V2 5/5] vhost: access vq metadata through kernel virtual address | From | Jason Wang <> | Date | Tue, 12 Mar 2019 15:15:22 +0800 |
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On 2019/3/12 上午11:50, Michael S. Tsirkin wrote: >>>> Using direct mapping (I >>>> guess kernel will always try hugepage for that?) should be better and we can >>>> even use it for the data transfer not only for the metadata. >>>> >>>> Thanks >>> We can't really. The big issue is get user pages. Doing that on data >>> path will be slower than copyXuser. >> I meant if we can find a way to avoid doing gup in datapath. E.g vhost >> maintain a range tree and add or remove ranges through MMU notifier. Then in >> datapath, if we find the range, then use direct mapping otherwise >> copy_to_user(). >> >> Thanks > We can try. But I'm not sure there's any reason to think there's any > locality there. >
Ok, but what kind of locality do you mean here?
Thanks
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