Messages in this thread | | | Subject | Re: performance bug in virtio net xdp | From | Jason Wang <> | Date | Wed, 6 May 2020 16:37:41 +0800 |
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On 2020/5/6 下午4:08, Michael S. Tsirkin wrote: > So for mergeable bufs, we use ewma machinery to guess the correct buffer > size. If we don't guess correctly, XDP has to do aggressive copies. > > Problem is, xdp paths do not update the ewma at all, except > sometimes with XDP_PASS. So whatever we happen to have > before we attach XDP, will mostly stay around.
It looks ok to me since we always use PAGE_SIZE when XDP is enabled in get_mergeable_buf_len()?
Thanks
> > The fix is probably to update ewma unconditionally. >
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